# View Zoom Math 400 User Guide Online

## The Power of Calculator Software!

# Zoom Math 400

## Version 1.00 User Guide

## Zoom Math 400

## Version 1.00 User Guide

Revised 7/27/2010

2010 I.Q. Joe, LLC www.zoommath.com

C H A P T E R 1

I N T R O D U C I N G Z O O M M A T H

“Features” not in Zoom Math

Zoom Math for Students

Zoom Math for Teachers and Tutors

Zoom Math for Professionals

The Five Editions of Zoom Math

C H A P T E R 2

I N S T A L L I N G Z O O M M A T H

Installation Requirements

Installing from Another Calculator

Installing from Your Computer

C H A P T E R 3

R E G I S T E R I N G Z O O M M A T H

Limitations of Unregistered Zoom Math 10

Finding Your Calculator’s zCode

Purchasing Your Registration Key

Entering Your Registration Key

10

11

11

2

2

1

2

3

7

8

9

C H A P T E R 4

U S I N G Z O O M M A T H

Getting Started with Zoom Math

Typing Expressions

-- Typing Negative Numbers

-- Typing Letters (Variables)

-- Typing

**Pi**

-- Typing Fractions

-- Typing Percentages

-- Typing Absolute Values

-- Typing Exponents

-- Typing Scientific Notation

15

16

-- Typing Square, Cube & Other Roots 16

--

Typing Imaginary & Complex Numbers

17

--

Typing Subscripts

17

14

14

15

15

12

13

13

13

-- Typing Sequences

-- Typing Repeating Decimals

-- Typing Logarithms

-- Typing Combinations etc.

17

18

18

18

-- Typing Σ for Summation Notation

-- Typing Math Menu Functions

18

19

-- Using Previous Answer in Calculations 19

-- Retyping Previous Problems

Editing Expressions

Using Equations

Viewing Answers

Unexpected Answers 24

Finding Equations of Lines & Parabolas 24

Graphing Equations

Viewing Graphs

24

26

20

20

21

23

Defining Functions

Showing Steps

The “ZOOM” Key

27

27

27

C H A P T E R 5

Z O O M 4 0 0 F E A T U R E S

Typing Trigonometric Problems

Trig Equations and Proofs

Solving Triangles

Systems of Nonlinear Equations

Sequence Definitions

28

30

31

34

34

C H A P T E R 6

Q U I C K R E F E R E N C E

Calculator Keys

C H A P T E R 7

T E C H N I C A L N O T E S

Program Limitations

Troubleshooting

37

41

42

I N T R O D U C I N G Z O O M M A T H

Chapter

1

## Introducing Zoom Math™

Zoom Math.

You’ll wonder how you ever got along without it!

The problem will look just right on your screen.

Zoom Math was invented by a math teacher who doesn’t think you should have to be a rocket scientist to use a graphing calculator. Install Zoom Math on your TI-83 Plus or TI-84 Plus graphing calculator, and instantly your calculator becomes easy to use!

Now you type math problems just the way they look in a textbook. Forget

“Calculatorspeak.” You won’t need it. You’ll wonder how you ever got along without

Zoom Math!

Margin tips like this one cover most of what you need to know.

If the tip starts with

“Zoom Faster!” it’s a shortcut!

## “Features” not in Zoom Math

Unlike other products, Zoom Math has…

No huge manual!

The TI-83 Plus Guidebook is hefty because many of the calculator’s functions are difficult to explain. Your Zoom Math User Guide is lean and simple because the software works the way you expect. In fact, by just reading the helpful margin tips, you can get started immediately. Later, refer back to this guide if you need more detailed help. If questions come up, you can find answers fast in the Quick Reference chapter.

You’ll be a math expert in no time!

Just enter a problem, and

Zoom Math does the math.

No complicated menus!

Zoom Math can solve many kinds of math problems, but it doesn't need to ask what kind of problem you're doing. Just type a problem and Zoom Math’s SmartFunction™ will figure out what to do without pesky questions or tiresome menus. Even if the problem is a mix of several types of problems, Zoom Math does the math for you!

Type a problem just the way it looks.

No weird key combinations!

Zoom Math is so easy to use, you can focus on the math instead of trying to remember which keys to press. Without Zoom Math, to type they look!

*a*

5

, you need to use the funky

**^**

key.

In Zoom Math, just type

*a*

then press

**5**

. In Zoom Math, you type problems the way

No confusion!

Even when you learn the weird key combinations, what you type won't look much like the problem in your textbook—unless you use Zoom Math. In Zoom Math, exponents always look like exponents. Fractions look like fractions. Variables are lowercase. Everything looks right on your calculator screen!

1

I N T R O D U C I N G Z O O M M A T H

Zoom Math:

Anyone can do math!

Zoom Math is allowed on the

SAT and AP exams!

Your students will love Zoom Math because it brings a difficult subject easily within their reach.

Zoom Math does for advanced math what calculators alone do for long division.

It’s a no-brainer!

The last time you did long division without a calculator was fifth grade. You wouldn’t chop down a tree with your bare hands. Why would you even consider doing math the hard way? Supercharge any TI-Plus Series graphing calculator with Zoom Math. With a power tool like Zoom Math, anyone can do math!

## Zoom Math for Students

Zoom Math is a super learning tool for math students. You can check assignments by comparing to Zoom Math results. If you made a mistake, Zoom Math can help you figure out where you went wrong. If you are taking a more advanced math or engineering course, Zoom Math can handle routine calculations, saving you from careless errors and freeing you to focus on new material. Best of all, Zoom Math is allowed on the SAT and AP exams!

## Zoom Math for Teachers and Tutors

Zoom Math is a wonderful tool for math teachers. Maybe you’re tired of spending so much effort teaching students how to use their graphing calculators. Or maybe you have disallowed graphing calculators because they cause more problems than they solve. Now things have changed. With Zoom Math loaded onto their graphing calculators, students feel empowered because their calculators are suddenly easy to use.

Suddenly math doesn’t seem so hard!

Zoom Math is also a useful tool for preparing lessons and tests. When formulating exam questions, use Zoom Math to quickly verify answers. Also, Zoom Math works in conjunction with TI Connect and your desktop computer to capture expressions and equations, as formatted by Zoom Math, and then include them in a document for printing.

Best of all, Zoom Math is compatible with TI presentation technology, including TI-

SmartView and TI-Navigator, so your entire class can follow along with you and

Zoom Math.

## Zoom Math for Professionals

Zoom Math is a great tool for those who are no longer students, but need to perform math calculations on the job. If your profession requires math skills, you’re not interested in the gory details. You just want quick, reliable solutions. Sure you could do long division on paper like your grandfather, but you’d much rather switch on a calculator and get dead-on, accurate answers in seconds. By solving math problems quickly and precisely, Zoom Math does for more advanced math what calculators did for long division!

2

I N T R O D U C I N G Z O O M M A T H

Try Zoom Math for no charge with

App4Math.

## The Five Editions of Zoom Math

This Zoom Math User Guide is for Zoom Math 400™.

Zoom Math comes in five different editions, so that you only have to purchase the level of math help that you need. Zoom Math Starter Edition – App4Math is the introductory level edition, and there are three advanced editions. Keep in mind that each higher-level edition can do everything the lower-level editions do, while adding more problem-solving capabilities designed to correspond with typical higher-level math courses taught in high school or college. In other words, if you are currently taking Pre-Algebra, but you know you will be taking Algebra 1 later, you can go ahead and purchase Zoom Math 200, because it will include all the problem-solving capabilities that help you in Pre-Algebra as well as the problem-solving capabilities you will need later when you take Algebra 1.

App4Math

The introductory-level edition of Zoom Math is Zoom Math Starter Edition, also known by the name App4Math. This edition is available free as a download from the

Zoom Math website, www.zoommath.com

, and now comes pre-installed on all TI-84

Plus Silver Edition calculators sold worldwide. Since App4Math is free proprietary software, we encourage you to transfer copies of App4Math to friends and classmates for them to use too. Zoom Math Starter Edition will appear on your calculator’s list of

Apps simply as App4Math. The Starter Edition of Zoom Math can perform calculations including:

• Pi (

**π**

)

• Fractions

• Percentages

• Absolute values

• Exponents

• Scientific notation

• Square roots, cube roots, and other roots

• Imaginary and complex numbers

• Logarithms

• Trigonometric functions

• The most commonly used Math Menu functions

App4Math also features the amazing ability to instantly change the mode of an answer.

You can instantly display answers as either:

• Decimals (including instantly changing precision)

• Fractions (including improper and mixed fractions)

• Percentages

• Scientific notation

• Quotients with remainders

3

I N T R O D U C I N G Z O O M M A T H

Even before you buy a Registration

Key, the free download of

Zoom Math 100 does more than

App4Math!

Most calculator functions, even graphing, can be accomplished in

Zoom Math when you upgrade to

Zoom Math 100.

And it shows steps!

The free download of Zoom Math 200 is like App4Math, and also does some graphing and some algebra.

Factoring polynomials or solving quadratic equations is very easy with

Zoom Math 200.

Zoom Math 100

The first advanced-level edition of Zoom Math is Zoom Math 100™. It will appear on your calculator’s list of Apps as Zoom100. Zoom Math 100 can be downloaded and installed free of charge, but will be unregistered on your calculator until a Registration

Key is purchased and entered.

Even before you purchase a Registration Key, Zoom Math 100 allows you to do everything App4Math does, plus a little bit of graphing, all for free. Purchase a

Registration Key to unlock more graphing and to show calculations one step at a time.

Once you have purchased your Registration Key, you can unlock all the features of the software. In addition to doing everything that App4Math can do, Zoom Math 100 can also:

• Graph equations with easier equation entry than when you are not using Zoom Math

• Graph most equations that begin with “*x* =” or “*y* =”

• Graph lines in standard form, such as 2*x* + 3*y* = 5

• Graph lines faster than when you are not using Zoom Math

• Label the *x*- and *y*-axes for easier readability, like in a textbook

• Use the arrow keys to move the view of a graph

• Use

**+**

and

**−**

keys to zoom in and zoom out when viewing a graph

• Instantly snap to a graph quadrant by pressing the number of that quadrant

• Instantly return to the origin by pressing

• Show solution steps for most problems

**0**

(zero)

Zoom Math 200

The second advanced-level edition of Zoom Math is Zoom Math 200™. It will appear on your calculator’s list of Apps as Zoom200. Zoom Math 200 can be downloaded and installed free of charge, but will be unregistered on your calculator until a

Registration Key is purchased and entered.

Even before you purchase a Registration Key, Zoom Math 200 allows you to do everything App4Math does, plus a little bit of graphing, and a little bit of algebra, all for free. Purchase a Registration Key to unlock more algebra, as well as the full graphing features from Zoom Math 100.

Once you have purchased your Registration Key, you can unlock all the features of the software. Zoom Math 200 will handle most equations up to and including those found in a typical Algebra 1 class. This means that in addition to doing everything that

App4Math and Zoom Math 100 can do, Zoom Math 200 can also:

• Combine like terms

• Simplify exponential expressions

• Distribute and FOIL

• Add, subtract, multiply and divide fractions containing variables

• Simplify square roots, cube roots, and other radicals

4

I N T R O D U C I N G Z O O M M A T H

Zoom Math 300 does everything that Zoom Math

200 can do, plus more Algebra 2 problems.

Zoom Math 300 can calculate the equation of a line.

Zoom Math 300 understands function notation, logarithms, summations, and combinations, permutations, and factorials.

• Substitute out variables with known values

• Solve multi-variable equations for a specific variable

• Solve systems of linear equations

• Add arithmetic sequences

• Factor polynomials

• Solve complicated fraction problems that involve factoring

• Divide polynomials

• Solve quadratic equations

• Solve equations that include square roots

Zoom Math 300

The third advanced-level edition of Zoom Math is Zoom Math 300™. It will appear on your calculator’s list of Apps as Zoom300. Zoom Math 300 can be downloaded and installed free of charge, but will be unregistered on your calculator until a

Registration Key is purchased and entered.

Without a Registration Key, Zoom Math 300 can do everything App4Math does, plus a little bit of graphing and a little bit of algebra.

After you purchase a Registration Key, Zoom Math 300 can do everything Zoom

Math 200 can do, and a few more things. Zoom Math 300 has some new Algebra 1 features. Zoom Math 300 can:

• Show more details when using the quadratic formula

• Show the steps of checking the answers of a rational equation or a radical equation

• Calculate the equation of a line through two given points

• Calculate the equation of a line with a given slope through a given point

With a Registration Key, Zoom Math 300 can also handle most equations found in a typical Algebra 2 class. This means that in addition to doing everything that Zoom

Math 200 can do, Zoom Math 300 can also:

• Solve non-quadratic equations that are in quadratic form

• Understand function notation such as f(x)=3x+5

• Calculate inverse functions

• Simplify, expand, and combine logarithms

• Solve logarithmic and exponential equations

• Evaluate expressions that use summation notation

• Add geometric sequences

• Convert repeating decimals to fractions

• Simplify expressions involving combinations, permutations, and factorials

• Find the equation of a parabola with a given vertex through a given point

5

I N T R O D U C I N G Z O O M M A T H

Zoom Math 400

The fourth advanced-level edition of Zoom Math is Zoom Math 400™. It will appear on your calculator’s list of Apps as Zoom400. Zoom Math 400 can be downloaded and installed free of charge, but will be unregistered on your calculator until a

Registration Key is purchased and entered.

Without a Registration Key, Zoom Math 400 can do everything App4Math does, plus a little bit of graphing and a little bit of algebra.

With a Registration Key, Zoom Math 400 can solve many Trigonometry problems.

With Zoom Math 400, you can:

• Type trig problems the way they look, without extra parentheses

• Easily type angles in degrees or radians, without complicated menus

• Type csc, sec, and cot

• Simplify complicated trigonometric expressions

• Solve equations that include trig functions

• Show step-by-step proofs of trig identities using **TRACE**

• Solve triangles using the Law of Sines or the Law of Cosines

• Calculate the points where two nonlinear equations intersect

• Define a recursive sequence and calculate a term in the sequence

We plan to create further advanced-level editions such as Zoom Math 500, but we have not yet announced a release date for any new products. Join our email list, and we will let you know when new products become available.

6

I N S T A L L I N G Z O O M M A T H

Chapter

2

## Installing Zoom Math

## Installation Requirements

CAUTION.

The finest software applications can cause inadvertent loss of data or other problems. It is possible that Zoom Math could crash and adversely affect the contents of your calculator’s memory. If your calculator RAM contains programs or other important data, we recommend you either save a backup copy of this information to your PC using appropriate TI tools, or refrain from using Zoom Math. Likewise, if your calculator stops responding to keyboard input (locks up), and will not turn off and back on with the corresponding keys, simply remove the AAA batteries (not the lithium) for a few seconds. Upon reinstalling the batteries the calculator should respond normally. Few users keep data in RAM, and problems are unlikely, but caution is advised.

You can install Zoom Math from another calculator, or from your computer. Installing

Zoom Math from another calculator is easier, but if you don’t know someone who already uses Zoom Math, you will need to install it from your computer after downloading it from the Zoom Math website.

You need at least 98304 ARC (calculator memory) free to install Zoom Math 400. You may need to delete unused Apps to make room for this software. Whatever you choose to delete, you might want to try running an App before you delete it, just to be certain you don't need it. All the Apps that were pre-installed on your calculator are available free from the TI website, so if you later need something that you've deleted, you can always re-install it. Consult your TI guidebook for instructions on deleting an

App and other procedures on managing memory.

7

I N S T A L L I N G Z O O M M A T H

Zoom Faster!

If someone else in your math class already uses

Zoom Math, ask him to copy it onto your calculator.

To run

Zoom Math 400, press APPS, find

Zoom400, then press ENTER.

## Installing Zoom Math from Another Calculator

1. Find a link cable and another calculator with Zoom Math already installed.

On that calculator: a. If Zoom Math is currently running, press

**2nd QUIT**

. b. Press

**2nd LINK**

. c. Press the down arrow repeatedly until you have selected

**C:Apps…**, then press

**ENTER**

. d. An alphabetical list of applications will appear. Select

***Zoom400 **

**APP**, then press

**ENTER**

. e. Press

►

once to highlight

**TRANSMIT**. Do *not* press

**ENTER **

yet.

2. Connect the two calculators using the link cable.

3. On your calculator: a. Press

**2nd LINK**

. b. Press

►

once to highlight

**RECEIVE**. c. Press

**ENTER**

.

4. Press

**ENTER**

on the transmitting calculator.

5. If you followed these steps and the link cable is working, your calculator should say,

**Receiving… *Zoom400 APP**. (Your calculator might say

**Garbage collecting…** instead. If that happens, just be patient.)

6. Wait for your calculator to say, **Done**. Then press

**2nd QUIT**

on both calculators. Zoom Math 400 is now on your calculator.

7. To run Zoom Math, press

**APPS**

. An alphabetical list of applications will appear. (This will be a very long list on some calculators.)

**Zoom400**

will be near the bottom of the list. Press

▲

to skip to the bottom of the list.

Then highlight **Zoom400** and press

**ENTER**

.

8

I N S T A L L I N G Z O O M M A T H

Zoom Faster!

If you know someone who already has

Zoom Math on his calculator, copy it from his calculator instead.

To run

Zoom Math 400, press APPS, find

Zoom400, then press ENTER.

## Installing Zoom Math from Your Computer

1. Before you can install Zoom Math from your computer, you may need to update your calculator's OS or download the latest version of TI Connect.

You can find step-by-step instructions at: http://education.ti.com/educationportal/sites/US/nonProductSingle/download.html

2. Follow the first 3 steps of the procedure on this web page, but don’t do step 4. Instead, download "Zoom400.8xk" onto your desktop. http://www.zoommath.com/downloads.html

)

(The most up-to-date version of the program can be downloaded at:

3. Make sure your calculator is on, and connected to your computer via the cable.

4. On your computer, run TI Connect.

5. Within TI Connect, run TI DeviceExplorer. A window should appear such as: "TI-84 Plus - TI DeviceExplorer."

6. Drag Zoom400.8xk onto "TI-84 Plus" (or whatever your calculator is) in the TI DeviceExplorer window. Another window should appear:

"Transferring..."

7. Wait a while. Soon, you should see a progress bar indicating how much longer you'll have to wait, or an error message if something went wrong.

8. After your computer finishes transferring Zoom400 onto your calculator, click on the little + sign next to the word "Applications." You should see some Apps listed now, including **Zoom400**.

9. If everything worked fine so far, then Zoom Math 400 is on your calculator now.

8. To run Zoom Math, press

**APPS**

. An alphabetical list of applications will appear. (This will be a very long list on some calculators.)

**Zoom400**

will be near the bottom of the list. Press

▲

to skip to the bottom of the list.

Then highlight **Zoom400** and press

**ENTER**

.

9

I N S T A L L I N G Z O O M M A T H

Chapter

3

## Registering Zoom Math

Register Zoom

Math 400 to solve most Trigonometry problems and see solution steps!

Press ZOOM to find the zCode for your calculator.

App4Math is the only edition of Zoom Math that is fully functional without entering a

Registration Key. Zoom Math 400 and all of the other advanced-level editions of

Zoom Math require the purchase of a Registration Key to unlock the full capabilities of the software. When you are ready to upgrade, visit www.zoommath.com

.

## Limitations of Unregistered Zoom Math

Unregistered Zoom Math 400 can:

• Do everything that App4Math can do (see page 3)

• Do everything that an unregistered copy of Zoom Math 100 can do (see page 4)

• Substitute out variables with known values

• Solve simple problems involving exponents and powers

• Combine like terms

• Solve problems using the distributive property and FOIL

• Simplify square roots and other radicals

• Convert degrees to radians

Anyone can use these features without purchasing a Registration Key

After you register, Zoom Math 400 can solve most Trigonometry problems. Every feature that is listed on pages 3-6 is available once you have registered your copy of

Zoom Math 400.

## Finding Your Calculator’s zCode™

To register Zoom Math, you will need the zCode that is unique to your calculator. To find your calculator’s zCode, run Zoom Math, and then go to the Zoom information screen by pressing

**ZOOM**

. Your zCode will be 12 letters separated into three groups.

Example: “tpnv-ftby-ttth”. Once you have purchased your Registration Key, press

**ENTER**

to continue to the registration screen where you can enter the Key.

10

I N S T A L L I N G Z O O M M A T H

Press ZOOM then

ENTER before entering your

Registration Key.

## Purchasing Your Registration Key

Installing Zoom Math on your calculator gives you access to the free features of

Zoom Math. Entering your Registration Key unlocks all the features of Zoom Math.

After you install Zoom Math on your calculator, you can buy a Registration Key at http://www.zoommath.com/register.html

.

After your payment clears, your Registration Key will be automatically emailed to you from [email protected]

. If you have not received your Registration Key within an hour (or within seven days when paying by eCheck), first check your spam filters to be sure the message was not misfiled, and then contact Zoom Math via our website, www.zoommath.com/contact.html

., or phone us at 888-ZOOM-APP.

## Entering Your Registration Key

To enter your Registration Key, start from the Zoom information screen which shows the zCode for your calculator. If you are not already on that screen, be sure

Zoom Math is running, then press

**ZOOM**

. From the Zoom information screen, just press

**ENTER**

to get to the registration screen. On the registration screen you can input your 10-digit Registration Key. Input your Key and then press

**ENTER**

. If you typed the correct key, you should get a message saying that all the features of Zoom Math 400 are now unlocked.

You won’t have to enter the Registration Key ever again, unless for some reason your flash memory is cleared. (This usually doesn’t happen even when you change the batteries.) We recommend that you write down your Registration Key just in case, but

Zoom Math can provide you with your Registration Key again if you ever lose it.

11

To run

Zoom Math 400, press APPS, find

Zoom400, and press ENTER.

Type a problem and then press

ENTER for the answer.

Q U I C K R E F E R E N C E

Chapter

4

## Using Zoom Math

## Getting Started with Zoom Math

To run Zoom Math 400, press

**APPS**

. An alphabetical list of applications will appear.

(This will be a very long list on some calculators.) **Zoom400** will be near the bottom of the list. Press

▲

to skip to the bottom of the list. (On the TI-84 Plus Silver Edition,

**ALPHA**

**Z**

will get you to the bottom of the list even faster.) Then highlight **Zoom400** and press

**ENTER**

.

Zoom Math begins with a title screen. Just wait a few moments and the title screen will go away on its own, or to avoid waiting, press any key to continue to the solution screen. The Zoom Math 400 solution screen is a blank display with

**Zoom Math 400 **

at the top. This is the main screen where you will type problems and get solutions.

To solve a problem, just type it exactly as it appears in a math textbook, and then press

**ENTER**

. If the problem is too long to fit on one line, type it normally, and Zoom Math will automatically wrap it to the next line. To correct anything that looks wrong, use the arrow keys to move the cursor to the offending spot, and then type the correction.

After you press

**ENTER**

, Zoom Math displays the answer in bold.

Zoom Math 400 can perform most calculations that you would normally use a calculator for, and it can also solve most problems you would encounter in a typical

Trigonometry or Precalculus textbook.

If the problem you want to solve does not include an equation or inequality then all you need to do is type the problem (see Typing Expressions below) and then press

**ENTER**

. Zoom Math will supply the equals sign as part of the answer.

If the problem you want to solve involves algebraic equations or inequalities, again, you simply type the problem (see Using Equations below) and press

**ENTER**

after each line of the problem.

To exit Zoom Math, press

**2nd QUIT**

.

12

U S I N G Z O O M M A T H

Most expressions can be typed just the way they look.

Zoom Math 400 treats uppercase and lowercase letters as separate variables.

Zoom Faster!

To repeat letters you’ve already used, press

X,T,**Ө**, n

.

## Typing Expressions

In Zoom Math, mathematical expressions can be typed on the calculator screen in the same way you would type them on the home screen of the calculator if you were not using Zoom Math. However, in Zoom Math, mathematical expressions look more like they do in a textbook. And most expressions can also be typed just the way they look.

Zoom Math also has some handy shortcuts that can make typing an expression easier and quicker than it would be if you were typing it on the home screen of the calculator.

Typing Negative Numbers

In Zoom Math you can use either the

**−**

(minus) key or the

**(**

**−)**

(negative) key to type a minus sign or a negative sign. These two keys are interchangeable in Zoom Math.

For clarity, when a negative sign follows an operator (

+

,

−

,

×

, or

÷

) Zoom Math will display the negative sign slightly smaller and slightly higher. For example, if you multiply six by negative three it will be displayed as negative two from five, it will be displayed as

**5 **

**− **

**− **

**2**

.

**6 × **

**− **

**3**

. Similarly, if you subtract

(Note: The positive sign acts in the same way. In other words, when it follows an operator, it is displayed slightly smaller and slightly higher.)

Typing Letters (Variables)

To type a letter, press

**ALPHA**

, and then press the key with that green letter above it.

You can type a capital letter by pressing

**ALPHA **

▲

, and then the letter. To switch back to lowercase letters, press

**ALPHA **

▼

.

In the calculator’s home screen, and in Zoom App4Math and Zoom Math 100, uppercase and lowercase versions of the same letter are treated as the same variable.

But in order to give you improved flexibility, Zoom Math 400 treats uppercase and lowercase versions of the same letter as two different variables which can have different values. As with App4Math and Zoom Math 100, lowercase

*e*

and

*i*

are reserved constants and cannot be used as variables. (Exception:

*i*

can be used as the variable in a summation notation.)

To repeat letters you have already used, press

**X,T,**

**Ө, n**

. The first time you press

**X,T,**

**Ө, n**

, the first letter you typed in the current problem will appear again. If you double-click

**X,T,**

**Ө, n**

, the second letter you typed will appear. If you keep pressing

**X,T,**

**Ө, n**

repeatedly,

Zoom Math will cycle through all the letters you have used in the current problem.

For example, if you already typed

*nk*

and now you want to type

2*nk*

, then you can just press

**2**

, then press

**X,T,**

**Ө, n**

once to get

*n*

, and then after a little pause, press

**X,T,**

**Ө, n**

twice quickly to get

*k*

. If you have not typed any letters yet, pressing

**X,T,**

**Ө, n**

will cause

*x*

to appear. Press

**X,T,**

**Ө, n**

twice quickly to get

*y*

, again quickly for

*z*

, again for

*a*

, then

*b*

, etc.

13

U S I N G Z O O M M A T H

**π**

is 2nd ^.

Zoom Faster!

To type a simple fraction, type the numerator, press

**÷**

, and then type the denominator.

To type a complicated fraction, press

**÷, **

then use the arrow keys.

If you press

**×**

when you have not used any letters in the current problem session,

Zoom Math will display the cross-shaped multiplication sign,

**×**

. After you have typed a letter, Zoom Math will change every multiplication sign into the dot multiplication sign, •, so that you won’t confuse the sign with the letter

X

. From that time on, the dot multiplication sign will remain in use until you end your problem session. (Exception:

In scientific notation the cross-shaped sign is always used.)

Typing

**π**

In Zoom Math, just as in the calculator’s home screen, you can press

**2nd **

**π**

(above the

**^**

key) to type

π

.

Typing Fractions

To type the fraction

1

, just press

**1 ÷ 2**

, and Zoom Math will automatically create the

2 fraction you want. You can type most fraction problems easily, without using arrow keys or parentheses. For example, to type

2

1

*x*

**1 ÷ 2 + 1 ÷ x**

.

(Note: When typing a fraction, if you begin the denominator by typing a number, any variable or operator (

+

,

−

,

×

, or

÷

) you type next will appear after the fraction. If you begin the denominator by typing a variable, any variable you type next will remain in the denominator, but any operator you type next will appear after the fraction. Before pressing another character, you can press

◄

to be sure to remain in the denominator, and you can press

►

to be sure to exit the fraction.)

To type a complicated fraction, first press denominator, press

►

to exit the fraction.

**÷**

. Zoom Math will create an empty fraction.

Type the numerator, then press

▼

, and then type the denominator. After typing the

For example, to type

*x y*

+

2

−

4

, press

**÷**

*x*

**+ 2**

▼

*y*

**−**

**4**

►

.

Or you can type complicated fractions by using parentheses. So another way to type

*x y*

+

−

2

4

is:

**( x + 2 ) ÷ ( y**

**−**

**4 )**

.

Zoom Faster!

Use

►

to make a space when typing a mixed fraction.

To type the mixed fraction

3

1

2

, type

3

, then a space, then

1 ÷ 2

. To type the space press either

►

, or

**ALPHA**

**0**

(zero).

If you actually want the calculator to show a division sign, double-click

**÷**

, and

Zoom Math will create a division sign instead of a fraction. So to type

15 ÷ 3

, you type

**15**

, double-click

**÷**

, and then press

**3**

.

14

U S I N G Z O O M M A T H

To type a percent sign, press 2nd

÷

.

To type absolute values use

**{ and }**

.

Zoom Faster!

Zoom Faster!

To type

3

, just double-click **x**

**2**

.

To type n

*5*

,

just press ALPHA n

5

.

To type a complicated exponent use ^ and the arrow keys or parentheses.

If you already created a fraction and want a division sign instead, highlight the fraction bar and then press

**÷**

. Similarly, to change a

**÷**

sign back into a fraction, move the cursor to the

**÷**

sign and press

**÷**

.

Typing Percentages

To type a percent sign, press

**2nd**

**÷**

. For example, to type

50%

, press

**5 0 **

**2nd**

**÷**

.

Typing Absolute Values

To type absolute value symbols use the

**{ }**

(curly brace) keys that are above the

**( )**

(parentheses). In other words, press

**2nd **

followed by

** (**

for the left side of an absolute value and

**2nd **

followed by

**)**

for the right side of an absolute value. So to type

|-6|

, you would press

**2nd**

** ( **

**- **

**6**

**2nd**

**)**

.

Typing Exponents

Typing an exponent after a variable is very easy. To type

*n*

5

, just press

**ALPHA**

*n* 5

. If you continue to type numbers they will remain in the exponent, so if you type

**ALPHA**

*n*

**1 2**

, Zoom Math will display

*n*

**12**

.

You can also press **x**

**2**

to square any expression. For example, to type

5

2

you can press

**5**

and then **x**

**2**

. To type

(3+1)

2

, press

**( 3 + 1 )**

**x**

**2**

.

(Note: If you use * x* the variable and then pressed

**2**

. So even though pressing

**3 **

*x*

pressing

**ALPHA**

*n*

*x*

**2**

to square a variable, Zoom Math treats it as if you had just typed

**2**

** 5**

will display

*n*

**25**

.)

**2**

** 5**

will display

**3**

**2**

**5**

,

To create an exponent of three, double-click * x* double-click

**x****2**

. For a power higher than gets up to the number you want.

3

**2**

. Each time you press * x* exponent will increase by one. For example, to type

5

3

, you can press

**5**

and then

, you can keep clicking **x**

**2**

**2**

quickly, the

until the exponent

The **x**

**-1**

*n*

-2

key works the same way as the **x**

**2**

, double-click **x**

**-1**

, and so on.

key. To type

*n*

-1

, press

**ALPHA**

*n*

**x**

**-1**

. To type

To use a variable in an exponent or type a more complicated exponent press

**^**

, and then type the exponent. For example, to type

2

*n*

, press

**2 ^**

**ALPHA**

*n*

.

After you type the first character in a complicated exponent, the cursor will appear to be partly below the exponent. If you press a number when the cursor is in this position, the number you typed will remain in the exponent. If you press an operator

(

**+**

,

**−**

,

**×**

, or

**÷**

), Zoom Math will assume you are done typing the exponent, so the operator you typed will appear outside the exponent.

(Note: If you press a letter when the cursor is partly below the exponent, and the first character in the exponent was also a letter, then the letter you typed will remain in the exponent. But if you press a letter when the cursor is in this position, and the first

15

U S I N G Z O O M M A T H

Type scientific notation with

2nd EE or 2nd 10 x

.

Type square roots the way they look.

Zoom Faster!

To type a cube root, just doubleclick ** **

**√**

**¯**

. character in the exponent was a number, then the letter you typed will appear outside the exponent.)

When the cursor is partly below the exponent, you can press

◄

to move the cursor completely inside the exponent. At any time, you can press

►

to move the cursor out of the exponent. For example, you can type

2

3+1

+ 4

by pressing

**2 ^ 3**

◄

**+ 1**

►

**+ 4**

.

Or you can type complicated exponents by using parentheses. If the first key you press inside an exponent is

**(**

, then everything you type will remain inside the exponent until you press

**)**

. When you press

**)**

, both parentheses will disappear, and the cursor will move out of the exponent. So another way to type

2

3+1

+ 4

is:

**2 ^ ( 3 + 1 ) + 4**

.

When you create an exponent, Zoom Math inserts parentheses around the exponent’s base if necessary. For example, if you type

*n* 3

and then press * x* show

**( n**

**3**

**)**

**2**

, not

*n*

**3 2**

.

**2**

, Zoom Math will

If you type a minus sign followed by any exponent key, **x**

**2**

, **x**

**-1**

sign is automatically pulled into the exponent. For example, one way to type

*n*

press

**ALPHA**

*n*

**−**

**x**

**2**

.

, or

**^**

, then the minus

-2

is to

Typing Scientific Notation

In the calculator’s home screen, you can press

**2nd EE**

to write a number in scientific notation. In Zoom Math, you can still press

**2nd EE**

, or you can press

**2nd 10**

*x*

. For example, to type

3.5 × 10

5

, press

**3 . 5 **

**2nd 10**

*x*

**5**

. When you press

**2nd 10**

*x*

, Zoom Math will automatically insert the correct symbols for “times 10 to the power of”. After using either of these two methods, the cursor will be in the exponent and exponent typing rules will be in effect.

Typing Square Roots, Cube Roots, and Other Roots

You can type most square root problems easily, without using arrow keys or parentheses. For example, to type

18

+

8

, just press

**2nd**

** √**

**¯**

**1 8 +**

**2nd**

** √**

**¯**

**8**

.

To type a cube root, press

**2nd **

and then rapidly double-click the

**√**

**¯ **key. The first time you press

**√**

**¯**, you will get a square root. The second time you press it, the square root will change into a cube root. If you keep pressing

**√**

**¯**, you will get a fourth root and above.

Or you can change a square root into a cube root by moving the cursor to where the

3 would go and pressing

**3**

. You can change a cube root back into a square root by highlighting the

3

and pressing

**DEL**

. You can switch between square roots and fourth roots or higher roots the same way.

After you type the first character inside a square root symbol, the cursor will appear to be partly inside the square root symbol and partly outside. If you press a letter or number when the cursor is in this position, the character you typed will remain inside the square root symbol. If you press an operator (

**+**

,

**−**

,

**×**

, or

**÷**

), Zoom Math will

16

U S I N G Z O O M M A T H

To type a complicated square root, use the arrow keys or parentheses.

Type imaginary and complex numbers the way they look.

Usually, you can type a subscript by pressing the down arrow key.

Zoom Faster!

Use … to replace the middle terms of a sequence. assume you are done typing the square root, so the character you typed will appear outside the square root symbol.

When the cursor is partly inside the square root symbol, you can press

◄

to move the cursor completely inside the square root symbol. At any time, you can press

►

to move the cursor out of the square root symbol. So, for example, you can type

*x*

+

1

+

4

by pressing

**2nd**

** √**

**¯**

*x*

◄

**+ 1**

►

**+ 4**

.

Or you can type complicated square roots by using parentheses. If the first key you press inside a square root is

**(**

root until you press

**)**

, then everything you type will remain inside the square

. When you press

**)**

, both parentheses will disappear, and the cursor will move out of the square root symbol. So another way to type

**2nd**

** √**

**¯**

**( x + 1 ) + 4**

.

*x*

+

1

+

4 is:

Typing Imaginary and Complex Numbers

In Zoom Math, lowercase

*i*

normally means the square root of negative one, not a variable. To type

*i*

, just

**ALPHA I**

and watch Zoom Math display imaginary and complex numbers just the way that they look in your textbook. (Exception: When you use lowercase *i* with a Σ symbol, Zoom Math 400 understands that *i* is the index of summation, not the square root of negative one.)

Typing Subscripts

To type a subscript, press the decimal point key and then press the down arrow.

Usually, you don’t even need to press the decimal point key—just press the down arrow. When you’re done typing a subscript, use the right arrow key to exit the subscript.

In Zoom Math 400, you can use subscripts for typing logarithms, combinations and permutations, and sequence definitions such as

*s*

*n*

= *n*

2

.

Typing Arithmetic Sequences and Geometric Sequences

To add up a long arithmetic sequence or geometric sequence, instead of typing all of the middle terms, you can type **…** by pressing the decimal point three times. Be sure to include at least the first two or three terms and the last term, and make sure the **…** is between two plus signs.

For example, to add up all the integers from 1 to 100, type

**1 + 2 + … + 100**

up all the even integers from

*n*

to 100, type

*n* + ( *n* + 2 ) + … + 100

powers of 2 from 4 to 256, type

**4 + 8 + 16 + … + 256**

.

. To add

. To add up all the

To add up an infinite geometric sequence, just end the sequence with … and leave out the last term. For example, you can type

**16 + 8 + 4 + 2 + … **

to add up an infinite geometric sequence where each number is half as much as the previous number.

17

U S I N G Z O O M M A T H

Zoom Math 400 understands repeating decimals such as

0.454545…

To type log

2

5, press the down arrow key before you type the 2.

Instead of typing

5 nCr 3, type

.

▼

5 ALPHA C 3.

Type ALPHA N

ALPHA . to get n!

To type Σ, press

2nd +. To type ∞, press 2nd 8.

Typing Repeating Decimals

To type a repeating decimal in Zoom Math 400, type a few digits of the repeating decimal, and then type

**…**

. For Zoom Math 400 to understand what you typed, you need to make sure you include the repeating digits at least twice in a row after the decimal point. For example, Zoom Math won’t understand what you mean by 1.414… because the digits “14” are included once after the decimal point. Instead, type

**1.41414…**

and Zoom Math will understand what you mean.

Typing Logarithms

When you type logarithms in Zoom Math 400, you don’t usually need to use parentheses. For example, if you want to calculate log 5 + log 2, you can just type log 5+log 2, not log(5)+log(2).

To type a logarithm with a base, press

**log**

▼

, and then type the base you want. For example, to type log

2

5, press

**log**

▼ **2 5**

.

In Zoom Math, just as in the calculator’s home screen, lowercase

*e*

always represents the base of the natural logarithm, not a variable. So to type

*e*

, you can press

**ALPHA E**

.

Since

*e x*

is a commonly used function, you can also press press

**ALPHA E**

followed by an exponent.

**2nd e**

*x*

as an alternate way to

Typing Combinations, Permutations, and Factorials

Zoom Math 400 uses the same style that most textbooks use for combinations and permutations: “Five choose three” is written as choose three, type

**.**

▼** 5 **

**ALPHA **

**C 3**

.

5

C

3

in Zoom Math 400. So to type five

Type permutations the same way you type combinations, but use the letter P instead of the letter C.

To type the exclamation point of a factorial symbol, press

**ALPHA **

and then the decimal point key.

Typing Σ for Summation Notation

To type Σ, press

**2nd **

**+**

. Zoom Math will fill in *i*=1 underneath the Σ, and Zoom Math will put the cursor above the Σ so you can type a number there. If you want to type ∞ above the Σ, press

**2nd **

**8**

. After you are done typing the number above the Σ, press the right arrow key to move the cursor out from above the Σ. If you want something other than *i*=1 underneath the Σ, then you can use the arrow keys to go below the Σ to change what’s there.

Remember, after you move the cursor out from above the Σ, you can usually use the

**X,T,**

**Ө, n **

key as a shortcut to type the letter

*i* (or whatever letter you are using as the index of summation).

18

U S I N G Z O O M M A T H

For example, to type

*n*

10

∑

=

1

*n*

, press

**2nd + 1 0 **

▼▼ ◄◄◄

**ALPHA N **

►►►►

** X,T,**

**Ө, n**

.

Press MATH to use

Math Menu functions.

Typing Math Menu Functions

There are many other functions that come with your TI calculator which are explained in the calculator’s guidebook. The only ones available in Zoom Math are those in the

Math Menu. These functions work the same way in Zoom Math as they do from the calculator’s home screen, so press

**MATH**

to access the menu from which you can select functions.

Use 2nd ANS to include your last answer in a new calculation.

Using Previous Answer in Calculations

If you want to use the answer that Zoom Math supplied in the previous problem as part of a new calculation, then you can do that easily using

**2nd ANS**

. When you press

**2nd ANS**

while typing a problem, Zoom Math will display

**Ans**

, which will represent the value of the previous answer.

For example, suppose you want to calculate the area of a circle with a circumference of

20

. First you calculate the radius, which is the circumference divided by

2

times it yourself: press

**2 0 ÷ 2**

◄

**2nd**

π

**ENTER**

π

. Try

. You may not see all the digits unless you press

►

to increase your decimal precision, but if you do increase that as much as you can, you should get

3.183098862

as your answer. Next, you know that area is

π

times the radius squared. You calculated the radius in the last step, so now you can use

**2nd**

**ANS**

to calculate the area, without needing to retype that long 10-digit answer. Press

**2nd**

**π**

**2nd ANS**

**x**

**2**

. The screen will display

**π**

** (Ans)**

**2**

. Press

**ENTER**

and you will have your solution.

If you round off an answer by pressing the arrow keys, then

Ans

will still contain the exact value of the answer, not the rounded-off value.

If a problem’s answer involves more than one number, or if the answer is a word such as

**false**

, then that answer will not be saved. For example, after you type the problem

2(*x *+ *y*)

,

Ans

is

2*x* + 2*y*

. If the next problem you type is

*x*

Zoom Math 400 will say

*x* = -6 or *x* = 1

, but

Ans

will still be

2*x* + 2*y*

.

2

+ 5*x* = 6

, then

When you first run Zoom Math 400,

Ans

will not contain any value until you have typed a problem. After you exit Zoom Math 400,

Ans

in the calculator’s home screen will not contain the answer to the last problem you typed in Zoom Math 400.

19

U S I N G Z O O M M A T H

Zoom Faster!

To retype a previous problem, start on a blank line and press

▲

.

To view previous problems, press

WINDOW, and then use the arrow keys.

If you make a mistake, use the arrow keys to go back and make your correction.

Retyping Previous Problems

You might want to retype a problem you’ve previously typed, so that you can modify it into a similar problem (see Editing Expressions below). Or you may want to evaluate an expression that you’ve just typed, but this time for a different value of

*x*

(see Using

Equations below). To do this, you can go back and retrieve previous lines that you’ve typed. Starting from a blank line (not a blank screen—if you clear the screen this won’t work) press

▲

. This will retype the previous line you typed back onto the screen.

Pressing

▲

again will retrieve the line you typed before that, and so on. If you go too far, pressing

▼

will bring you back to the more recent lines.

If you want to go back and look at previous lines you’ve typed, you can press the

**WINDOW**

key, and that will put you in a mode where you can scroll around. That is, you can then use the arrow keys to move the screen view to look at previous things you’ve typed.

## Editing Expressions

If you make a typing mistake, use

◄

and

►

to move the cursor to the location of the mistake. To jump to the beginning of the current line, press

**2nd **

◄

. To jump to the end of the current line, press

**2nd **

►

. Use

▲

and

▼

to move the cursor between the numerator and denominator of a fraction.

If you type a problem that is too long to fit on one line, Zoom Math will usually break it into separate lines for you. If this happens, you must still use

◄

and

►

to move the cursor, just as if the whole problem were displayed on one line.

If you type a 20-digit number or a fraction too wide for the screen, and Zoom Math cannot find a good place to insert a line break, then Zoom Math will automatically scroll to the right so that your current typing will still stay on the screen. In such a case, you can use the

**WINDOW**

key followed by the

◄

key to move the screen view back to the left.

If you want to replace a character, move the cursor onto that character and type the new character. Or you can delete the character by pressing

**DEL**

. To insert characters, first press

**2nd INS**

to activate the insertion cursor. This cursor appears between two characters, not on top of a character. After you have inserted the desired characters, press

**2nd INS**

to deactivate the insertion cursor.

You can also use

**DEL**

as a backspace key as long as you are at the end of a line. So if you are at the very end of a line and hit

**DEL**

it will delete the previous character you just typed.

If you want to start over, press

**CLEAR**

to erase the current line. If the current line is already empty, press

**CLEAR**

to erase the whole screen.

20

U S I N G Z O O M M A T H

To type an equals sign, press **Y=**.

Use the equals sign to assign values to variables.

Then you can evaluate expressions.

To change a fraction bar into a

÷

sign, move the cursor onto the fraction bar and press

**÷**

. Zoom Math will insert parentheses around the former numerator and/or denominator if necessary. Similarly, to change a

÷

sign into a fraction, move the cursor to the

÷

sign and press

**÷**

, and Zoom Math will remove parentheses if appropriate.

Here is an example of editing an expression. (Follow along on your calculator to see what happens.) Suppose you want to type

1

+

4

2

+

+

5

3

, but you forget to press

**÷**

first to create a complicated fraction. You press

**1 + 2 + 3 ÷ 4**

. Then you notice something is wrong—the calculator says

1

+

2

+

3

. To fix this, press

▲

**÷**

to turn the fraction bar

4 into a

÷

sign. Then press

**2nd **

◄

**2nd INS**

**(**

** 2nd **

► ◄ ◄

**)**

**2nd INS**

to insert parentheses around the numerator. Finally, press

**÷**

to change the

÷

sign back into a fraction bar.

Because you inserted parentheses, Zoom Math now displays the numerator you wanted. Now you can press

▼ ►

and finish typing the problem.

## Using Equations

Press the

**Y=**

key to type an equals sign. It is the upper left key, farthest to the left in the very top row on your calculator, directly underneath your screen. To help with graphing, pressing

**Y=**

at the beginning of a line types

*y* =

.

There are four uses for the equals sign in Zoom Math 400. When you type your problem, Zoom Math’s SmartFunction™ will figure out which of the four uses for the equals sign applies in the current problem.

The first way to use an equals sign is to assign a value to a variable. If the left side of an equation is just one variable, SmartFunction™ will assign the value of the expression on the right side of the equation to that variable. For example, you can type

*x* = 3

**ENTER**

, to assign the value

3

to

*x*

. (Don’t forget you can use the

**X,T,**

**Ө, n**

key as a shortcut to type

*x*

.) Then you can use that variable to evaluate an expression, or in other words see what happens when you plug the value of that variable into an expression. For example, if you need to evaluate then

**2 x 2 **

**ENTER**

.

2*x*

2

when

*x* = 3

, type

*x* = 3

**ENTER**

and

If you want to evaluate an expression for several different values of

*x*

, you can continue by assigning a new value to

*x*

, then using

▲

to retrieve the expression you are evaluating. So to continue the above example, after you saw that now you want to know what it would be when

*x* = 5

. Type

*x* = 5

**ENTER**

, and then press

▲

twice to retype

2*x*

2

. (The first time you press again.) Now when you press

**ENTER**

you will see that

2*x*

▲

2*x*

2

is

18

when

*x* = 3

,

you will see the

2

is

50

when

*x* = 5

.

*x* = 5

line

You can also assign a calculated value to a variable. For example, if you type

*x* = 3 + 2

**ENTER**

, then from that point forward, until you change the value of

*x*

, it will represent the number

5

.

21

U S I N G Z O O M M A T H

To prevent variables from being cleared, delete the problem divider after solving a problem.

You can also use the equals sign to evaluate equations.

Inequalities can also be evaluated.

To solve a system of equations, press

ENTER after typing each line.

Zoom Math 400 will try to determine when you are finished with a problem, and will then print a dotted line as a problem divider. After a problem divider, Zoom Math 400 does not pay any attention to the variable values from the previous problem, so if you want to continue using those values, then you should delete the problem divider by immediately pressing

**DEL**

.

Remember that unlike the calculator’s home screen, Zoom Math 400 treats uppercase and lowercase versions of the same letter as two different variables. So, for example,

*X*

and

*x*

will *NOT* represent exactly the same value, unless you assign the same value to each separately.

If you want to know the current value assigned to a variable, you can easily check at any point in a problem by typing the variable as a new line, and then pressing

**ENTER**

.

Lowercase

*i*

and

*e*

* *are reserved constants (

*i*

is the square root of

-1

and

*e*

is the base of a natural logarithm), so you may not assign any new value to them. However if you wish, you may assign values to uppercase

*I*

and

*E*

, and they can be used like any other variable without affecting the reserved constants.

The second way to use an equals sign is to evaluate an equation. If you have already assigned values to variables in the current problem, and now type a line where the left side of an equation is more than just one variable, SmartFunction™ will evaluate an equation to see if it is true or false. For example, if you have already assigned a value to

*x*

and then type

*x* + 2 = 3

**ENTER**

, Zoom Math will treat this as the question, “Does the current value of

*x*

plus

2

equal

3

?” Zoom Math will give you a

**true**

or

**false**

answer.

You can also ask about comparisons using “less than”, “greater than”, “less than or equal to”, and “greater than or equal to”. To type “less than” (

<

) press

**ALPHA**

◄

.

“Greater than” (

>

) is

**ALPHA**

►

. “Less than or equal to” (

≤

) is

**ALPHA**

◄** **

**Y=**

. And

“greater than or equal to” (

≥

) is

**ALPHA**

►** **

**Y=**

. So for example, if you type

*x* = 3

**ENTER**

, followed by

*x *2

**ALPHA**

◄** 10 **

**ENTER**

, Zoom Math will answer

**true**

, since

*x*

2 is less than

10

.

is

9

, which

When evaluating equations or inequalities, the expression evaluated must contain only one relational operator, and it must not be within parentheses, within fractions or within anything else.

The third way to use an equals sign is to graph equations. See “Graphing Equations” below.

The fourth way to use an equals sign is to solve algebraic equations.

If the problem you want to solve involves algebraic equations or inequalities, again, you simply type the problem and press

**ENTER**

after each line of the problem. This is how you would solve the following types of problems:

• Linear equations and inequalities

• Systems of linear equations

22

U S I N G Z O O M M A T H

Use

►

and

◄

to change the decimal precision of an answer.

Zoom Faster!

Use MODE to cycle through all possible answer modes.

• Quadratic equations

• Radical equations

Please note that with these types of problems, Zoom Math will use SmartFunction to figure out when you have completed the problem. For example, Zoom Math knows that if you want to find the values of two variables, you need to have two equations. So if you type something like

*x* + *y* = 5

and press

**ENTER**

, Zoom Math will not give you an answer. Instead, Zoom Math will wait for you to type a second equation involving

*x*

and

*y*

. After you enter the second equation, Zoom Math will give you the answer.

## Viewing Answers

You can change the form of your answer quickly and easily in Zoom Math. Type

16 **÷ **

7

, double-clicking

**÷**

to get a division sign, not a fraction:

**16 ÷ ÷ 7 **

**ENTER**

. You’ll get an answer with three decimal places of accuracy. You can quickly increase the precision by pressing

►

a few times, or move it back to fewer decimal places by pressing

◄

a few times. You can also change the answer to a fraction just by pressing

**÷**

, and you can change the form of the fraction to a mixed fraction by pressing

**÷**

again. If you used the division symbol (not a fraction) to divide a positive integer by a positive integer, then you can press

**÷**

a third time, and you will see the answer as a quotient with a remainder.

There are a couple of other ways to display answers as well. To see your answer as a percentage, press

**2nd **

**÷**

. To see your answer in scientific notation, press

**^**

. (

**2nd EE**

and

**2nd 10**

*x*

also display scientific notation.) Finally, to return to seeing your answer as a decimal, press the

**.**

(decimal point) key.

Whatever form of answer you end up in when you finish a problem will be your default form for the answer to your next problem. Of course, if you don’t like the form of a new answer, it will now be easy for you to change it. If you forget how to get a specific form you’re looking for, or just want to play with it for fun, you can use the

**MODE**

key to cycle through all the possible answer forms.

While you are viewing various forms of your answer, you are in answer mode. You enter answer mode by pressing any of the keys described above that can change the form of your answer. These keys are known collectively as mode keys. (The

◄

and

► keys are not included as mode keys, because they only change decimal precision, not the form of your answer.)

If you are in answer mode, but want to return to the problem you just typed instead of starting a new problem, just press

**CLEAR**

to clear the answer from the screen.

23

U S I N G Z O O M M A T H

Want an answer in a different form? If

MODE doesn’t help, try 2nd ANS

ENTER.

To find the equation of a line between two points, type the two points separated by a comma.

To graph, just press GRAPH instead of ENTER.

## Unexpected Answers

Sometimes Zoom Math 400 will give you an answer that is correct, but is not the answer you expected. For example, if you type

*x*

2

+ 2*x* + 3*x* + 6 will add the like terms

2*x*

and

3*x*

, giving you the answer

*x*

answer. But what if you wanted Zoom Math to factor?

, then Zoom Math 400

**2**

** + 5 x + 6**

. That’s a correct

When Zoom Math 400 gives you an answer in a different form than you expected, try pressing the

**MODE**

key. If that doesn’t help, try typing

**2nd ANS ENTER**

. For example, if you get the answer

*x*

**( x + 2 ) ( x + 3 )**

.

**2**

** + 5 x + 6**

, but you were expecting a factored answer, then go on to the next problem and type

**Ans**

. Now Zoom Math will factor, giving you the answer

## Finding Equations of Lines and Parabolas

To find the equation of a line between two points, type the first point, then type a comma, and then type the second point. For example, to find the equation of the line between (0,4) and (3,5), type ** (0,4),(3,5)**.

To find the equation of a line with a given slope through a given point, type **m = **the given slope, then a comma, and then the given point. For example, to find the equation of the line with slope 2 through the point (3,5), type **m=2,(3,5)** .

To find the equation of a parabola with a given vertex through a given point, type

**v = **

the given vertex, then a comma, and then the given point. For example, to find the equation of the parabola with vertex (0,0) through the point (1,1), type

**v=(0,0),(1,1)**.

After you find the equation of a line or parabola, you can press

**GRAPH**

to see the graph of the line or parabola.

## Graphing Equations

Zoom Math 400 can graph most functions. Zoom Math 400 can graph most equations that begin with

*y* =

or

*x*=. And Zoom Math 400 can graph most linear equations, even if they are not solved for

*x*

or

*y*

.

Zoom Math 400 can also graph a line between two given points, or a line with a given slope through a given point, or a parabola with a given vertex through a given point.

See the section “Finding Equations of Lines and Parabolas” on page 23 for more details.

In Zoom Math, you can graph equations using the same keystroke sequence that you would use in the calculator’s home screen. For example, to graph the line

*y* = 2*x*

in

Zoom Math, just type

**Y=**

** 2 x **

**GRAPH**

.

24

U S I N G Z O O M M A T H

Zoom Faster!

Let Zoom type the y

= for you!

Register your

Zoom Math 400 to graph complicated equations.

In Zoom Math, you don’t actually need to type the

*y* =

part. Just type an expression, such as

*x* + 2

, and then press

**GRAPH**

. Zoom Math will automatically insert the

*y* =

for you and then graph the equation.

If Zoom Math is unregistered on your calculator, you will only be able to graph very simple equations. If you have registered Zoom Math on your calculator, you will be able to graph more complicated equations. For example, an unregistered copy of

Zoom Math can graph the equation

*y* = 2*x*

or the equation

*y* = *x* + 3

, but not the equation

*y* = 2*x* + 3

.

When you press

**GRAPH**

Zoom Math will graph all of the equations you typed since the last problem divider. Problem dividers take the form of a dotted line across your screen. If you are on a blank line immediately following a problem divider, Zoom Math will graph all of the equations you typed between that divider and the previous problem divider. Also, if you are on a blank line immediately after a problem divider, pressing

**DEL**

will get rid of the problem divider. If you want to insert a problem divider where Zoom Math has not put one, you can press

**ENTER**

at the start of a blank line.

If you want to graph more than one equation, then press

**ENTER**

after you type each equation until you get to the last equation. On the last equation that you want to graph, press

**GRAPH**

instead of

**ENTER**

. For example, if you want to graph the equations

*y* = *x *+ 1

and

*y* = *x* + 2

, type

**Y=**

** x + 1 **

**ENTER Y=**

** x + 2 **

**GRAPH**

.

Remember, if you type two linear equations involving

*x*

and

*y*

, then Zoom Math 400 will use algebra to calculate the values of x and y where those two lines intersect. After

Zoom Math 400 calculates the answer, it prints a problem divider.

So if you want to graph three linear equations on the same screen, you can expect

Zoom Math 400 to interrupt with a calculated answer after you type the second equation. Just ignore this answer, press

**ENTER**

to go on to the next line, and then press

**DEL**

to delete the problem divider. Now type the third equation and press

**GRAPH**

.

Zoom Math 400 will graph all three linear equations on the same screen, ignoring the calculated answer to the first two equations.

For example, if you want to graph the three equations

*y* = *x *+ 1

,

*y* = 2*x*

, and

*y* = *x* + 3

, then after you type the second equation, Zoom Math 400 will display the solution for the first two equations you typed:

*x*=1, *y*=2

. Press

**ENTER**

to go on to the next line, press

**DEL**

to delete the problem divider, and then type the third equation and press

**GRAPH**

.

You can use

**Ans**

in an equation that you graph. (Press

**2nd ANS**

to type

**Ans**

.) For example, if you typed

**2 + 2 **

**ENTER**

, you will get the answer

**4**

. On the next line if you type

**Y=**

** x + **

**ANS GRAPH**

, then that will have the same effect as if you typed

**Y=**

** x + 4 **

**GRAPH**

.

25

U S I N G Z O O M M A T H

Use

◄

,

►

,

▲

,

▼

,

**+**

and

**−**

to view graphs.

Zoom Faster!

Press

**0**

to jump to the origin or a quadrant number to jump to that quadrant.

If you type an equation that Zoom Math cannot graph, then you might get an error message or Zoom Math might just show you graphing axes without a graphed equation on them. For example; if you type

**Y=**

** y + y **

**GRAPH**

, then Zoom Math will give you an error message. If you type

**Y=**

** x ÷ 0 **

**GRAPH**

, then Zoom Math will just show you an empty graph. If you try to graph more than one equation at a time, then

Zoom Math may give you an error message for one of the equations but go ahead and show you the graph of the other equations which do not contain errors.

## Viewing Graphs

The Zoom Math graphing screen features

*x*

- and

*y*

-axes which are labeled numerically in order to make it easier to read the graph.

If you want to get a better view of a graph you can use the arrow keys to move the graph. Press the

**+**

key to zoom in for a closer view of a graph. Press the

**−**

key to zoom out. If you move very far away from the origin, or if you zoom very far in or very far out, then Zoom Math may not label the axes anymore.

To quickly view a particular quadrant of the graph, press the number of that quadrant.

For example, to jump to quadrant I, press

**1**

. To return to the origin press

**0**

(zero).

When you are finished viewing a graph and want to return to the solution screen, press

**GRAPH**

,

**ENTER**

or

**CLEAR**

. Zoom Math will automatically insert a problem divider after the equations you just graphed, in preparation for your next problem.

Even though a problem divider is inserted when you return to the solution screen, it is still easy to go back to the graph you just viewed. Just press

**GRAPH**

while you are on a blank line immediately following the problem divider. Also, if you are on a blank line immediately after a problem divider, pressing

**DEL**

will get rid of the problem divider.

In certain cases, some tick marks will not be labeled if that would make the graph harder to read. For example, if you graph the parabola

*y* = *x*

2

, the number two on the

*y*

axis will not be labeled, because the label would appear right on top of the graph of the parabola. If you want to see the missing labels, press

**MODE**

to make all the graph labels appear. Press

**MODE**

again to return to the normal graph mode.

At this time Zoom Math graphing does not have

**WINDOW**

,

**TRACE**

or

**2nd CALC**

features. If there is a graphing feature that you want Zoom Math to include in the future, feel free to contact us via our website, www.zoommath.com/contact.html

.

26

U S I N G Z O O M M A T H

To define a function, just type the definition the way it looks.

To show steps, press TRACE instead of ENTER.

Need more help?

Press ZOOM.

## Defining Functions

To define a function such as

*f*

−

1

(

*x*

) simply by typing

*f*

−

1

(

*x f*

)

(

*x*

)

=

3

** ENTER**

*x*

.

, just type the function definition the way it looks. After you define the function

*f*(*x*), you can calculate the inverse function

Zoom Math 400 only understands functions named *f*, *g*, or *h*. If you type

Zoom Math will not understand that you are trying to define a function.

*x*

(

*t*

) 3

*t*

## Showing Steps

To see the steps of a solution, press

**TRACE**

instead of

**ENTER**

. The first time you press

**TRACE**

, the calculator will show you the first step. To go on to the next step, press either

**TRACE**

or

►

. To go back a step, press

◄

. If you want to see a more detailed step, press

▲

; or if you want to see less detail, press

▼

. To erase all the steps and return to the problem you typed, press

**CLEAR**

. To see all remaining steps and go on to the next problem, press

**ENTER**

.

While you are in

**TRACE**

mode, you cannot change the way steps look with the

**MODE**

key. Once you see the bold answer to your problem, you are ready to enter answer mode. Then you can press any mode key to enter answer mode and change the way your answer is displayed.

If you have reached answer mode after being in

**TRACE**

mode, you must press a mode key before you can use

◄

or

►

to change your answer’s decimal precision. If you do not press a mode key first, pressing

◄

or

►

will keep you in

**TRACE**

mode.

If you have pressed a mode key to enter answer mode, you can return to

**TRACE**

mode by pressing

**TRACE**

again. You might want to do this in order to be able to use

◄

again to back up a step, instead of to change the decimal precision of your answer.

## The “ZOOM” Key

Press

**ZOOM**

to go to the Zoom information screen. This screen tells which edition of

Zoom Math is installed on your calculator, the version number of that edition, and your calculator’s unique zCode, used in registering Zoom Math.

From time to time, you may want to compare the version number of your copy of

Zoom Math to the latest version listed on the Zoom Math website, to be sure you have installed the most recent update. Visit the Zoom Math Help Center at www.zoommath.com/help.html

for help using Zoom Math, to find the most recent update of Zoom Math, or to download the most recent version of this user guide.

27

To type a degrees symbol, doubleclick

^**.**

U S I N G Z O O M M A T H

Chapter

5

## Zoom400 Features

Answers to some of the examples in this chapter are in decimal. Other answers are in exact answer mode. If you get an answer that’s in a different form than our answer in an example, press

**MODE**

to switch formats. To round off an answer to fewer decimal places, press

◄

.

## Typing Trigonometric Problems

If you’ve ever tried to type a sine in Zoom Math 300 or if you’ve ever tried to type it in the calculator’s home screen without Zoom Math, then you know that ordinarily when you press

**SIN**

the calculator doesn’t just say

**sin**

; it adds an extra left parenthesis. In

Zoom Math 400, when you press the key that says

**SIN**

, all you get is the word

**sin**

; there’s no extra parenthesis. You can type problems involving sin

, cos

, and tan

the way they look.

Also, if you want to type an angle in degrees in the calculator’s normal operating system, you have to make sure the calculator is in degrees mode. In Zoom Math, you just type the angle the way it looks. If you want to calculate the sine of 30 degrees, you don’t type

**sin(30)**

; you type

**sin 30°**

.

To type a degrees symbol, double-click

**^**

.

Don’t forget the degrees symbol! In Zoom Math if you type

**SIN**

**3 0**

**ENTER**

without a degrees symbol, then Zoom Math will calculate the sine of 30 radians. That’s probably not what you want.

28

U S I N G Z O O M M A T H

If you want to convert degrees to radians, just type the number of degrees and press

**ENTER**

. If you want to convert radians to degrees, you will have to type the number of radians multiplied by

180

°

π

.

To type csc, press

2nd SIN.

To type sec, press

2nd COS.

To type cot, press

2nd TAN.

To type sin

−1

, press

SIN **x**

−1

**.**

Zoom400 understands csc

, sec

, and cot

. To type csc

, press

**2nd SIN**

; to type sec

, press

**2nd COS**

; and to type cot

, press

**2nd TAN**

.

If you look at the keys on your calculator, it looks like pressing

**2nd SIN**

would not type

**csc**

; it looks like it would type

**SIN**

**-1**

. But that’s not how it works in Zoom Math 400. In

Zoom Math 400, pressing

**2nd SIN**

will give you

**csc**

. If you actually want to type

**sin**

**−1**

press

**SIN**

and then **x**

**-1**

. To get

**cos**

**−1**

or

**tan**

**−1**

, press

**COS**

or

**TAN**

and then **x**

**-1**

.

,

When you type a problem like cos

−1

−1

, you might want the answer in degrees, or you might want it in radians. Zoom400 doesn’t know for sure which one you want, so

Zoom400 will try to figure it out based on the previous problems you typed. If the last problem you typed had degrees in it, then Zoom Math will give an answer in degrees.

If the last problem you typed had radians in it, then Zoom Math will give an answer in radians. This screenshot shows how you can switch between degrees mode and radians mode, just by typing problems that include degrees or radians.

If an answer could be in degrees or radians, Zoom

Math will decide which way to answer based on the last problem you typed.

29

U S I N G Z O O M M A T H

Zoom Math 400 can simplify trig expressions, solve trig equations, and prove trig identities.

## Trigonometric Expressions, Equations, and Proofs

Zoom400 can simplify trigonometric expressions by using trig identities.

Zoom400 can also solve equations that involve trig functions. When a trig equation has multiple answers, Zoom Math 400 will usually give only one answer. For example, entering the problem tan *x *= 1

will result in the answer

**45°**

, but not the answer

**225°**

or the answer

**405°**

.

30

U S I N G Z O O M M A T H

2

+

2

Zoom400 can also do trig proofs. If you type sin

*x*

cos

*x*

= sec

*x*

and press

**ENTER**

cos

*x*

, Zoom 400 will just say

**true**

. But if you press

**TRACE**

to show each step, Zoom

Math will show *why* it is true for all values of

*x*

.

Once you type enough information about a triangle, Zoom

Math 400 will solve the triangle.

## Solving Triangles

Zoom Math can solve triangles if you give it enough information. For example, if you know two angles of a triangle and one of the side lengths, then you can type that information into Zoom Math, and Zoom Math will calculate the other angle and the other two side lengths for you.

31

U S I N G Z O O M M A T H

To type an angle, press 2nd ANGLE.

Then type the letter.

In some textbooks, if you have a Δ

*ABC * then each side is labeled with the same letter as the opposite angle, like in the diagram below. Zoom Math expects you to use lowercase letters to refer to side lengths, like the triangle in the diagram.

*B c a*

*A b C*

(Some textbooks write the length of a side opposite ∠

*C*

as

*AB. *

Don’t type

*AB*

in

Zoom Math. Type

*c*

instead.)

To type an angle, press

**2nd ANGLE.**

(

**ANGLE**

is the

**2nd**

function of the

**APPS**

key.) If you press

**ALPHA **

right after you type an angle symbol, Zoom Math will automatically switch to uppercase mode for that letter. (This is probably what you expect anyway – angles are always written with capital letters.)

For example, if you want to type ∠

*A *= 45°

, ∠

*B *= 60°

,

*c *= 3

, press:

**2nd ANGLE ALPHA**

** A = 4 5 ^^ **

**ENTER **

**2nd ANGLE ALPHA**

** B = 6 0 ^^**

**ENTER **

**ALPHA c = 3**

**ENTER**

.

These three equations give Zoom Math enough information to solve the triangle. After you type the third equation, Zoom Math will think for a while, and then Zoom Math will tell you what the other angle and the other two sides of the triangle are.

Zoom Math can solve triangles, but it can’t solve parallelograms or any other geometric shapes. Don’t try to type information about any other shape.

32

U S I N G Z O O M M A T H

Sometimes you can give Zoom Math enough information to solve a triangle without actually telling Zoom Math all of the letters that are in the triangle. For example, if you say ∠

*A* = 30°

, ∠

*B* = 20°

,

*a* = 10

, then Zoom Math has enough information to solve the triangle, but Zoom Math doesn’t know all the letters that are involved yet. The triangle is

*A*

,

*B*

, and something else. When this happens, Zoom Math will guess another letter and give you the answer using that letter. For example, if you use the letters

*A*

and

*B*

, Zoom Math will guess that the other letter of the triangle is

*C*

.

After you type the lengths of three sides of a triangle,

Zoom Math won’t solve the triangle until you type the name of an angle.

If you know the three sides of a triangle and you want Zoom Math to calculate the angles, you’ll have to specifically ask for an angle.

After you type:

*a *= 3

*b *= 4

*c *= 5

Zoom Math won’t be sure yet that this is a triangle problem. Just type

**ANGLE**

**A**

**ENTER**

. Then Zoom Math will calculate the value of ∠

*A*

, and also the values of ∠

*B*

and ∠

*C*

.

33

U S I N G Z O O M M A T H

To solve a system of nonlinear equations, press

ENTER after typing each line.

## Systems of Nonlinear Equations

Zoom400 can find the points of intersection of two circles, or of a line and a circle.

Simply type the first equation, press

**ENTER**

, and then type the second equation. If

Zoom Math 400 can solve the system of equations, then it will. This might take a very long time. Zoom Math is very slow on these problems, especially if you

**TRACE**

each step.

To type a subscript, press the down arrow.

## Sequence Definitions

Zoom Math 400 understands definitions of sequences. For example, if you tell it that

*s*

*n*

= *n*

2

, then when you type

*s*

3

, it will get the answer

9

. To type a subscript, press the down arrow. (If you’re in the top of a fraction, press the decimal point key first.)

To type the example above, you would press

**s**

**▼ n = n 2**

**ENTER**

, then

**s**

**▼ 3**

** ENTER**

.

When you press

**ENTER **

the second time Zoom Math will display the answer

**9**

.

34

U S I N G Z O O M M A T H

If you want to find a different term in the same sequence, press

**ENTER**

to go on to the next line, and then press

**DEL**

to delete the dotted line. Now you can type

*s*

Math will understand that this is part of the same problem.

7

, and Zoom

Zoom400 even understands recursive sequence definitions.

When you want to type

*s*

*n*-1

, be careful. After you type the letter

*n*

, the cursor looks like it’s partly inside the subscript and partly outside the subscript.

35

U S I N G Z O O M M A T H

To put the minus sign in the subscript, you must press the left arrow first. Then you can finish typing the subscript.

You can use

**TRACE **

to show the steps of solving a recursive sequence, but the steps may be a little different than you would expect. Most people would calculate

*s*

2

, then

*s*

then

*s*

4

, and then

*s*

5

. When Zoom Math calculates the value of

*s*

5

3

,

, Zoom Math works backwards. Don’t worry; the Zoom Math way of solving the problem is still correct.

36

Q U I C K R E F E R E N C E

Chapter

6

## Quick Reference

## Calculator Keys

Top Row Function Keys

**Y=**

**WINDOW**

**ZOOM**

**TRACE**

Types an equals sign. Types

*y* =

when beginning a line.

Enters

**WINDOW**

mode, which allows you to look at previous problems or an answer too large to fit on one screen. Press a second time to return to normal operation.

Displays the Zoom information screen.

**GRAPH**

Shows the first step of a solution. Press again for each additional step, until the answer is reached.

Graphs one or more equations. If you are already viewing a graph, returns you to the solution screen.

Arrow (Cursor) Keys

All

▲

◄

►** **

▼** **

Navigate menu choices.

Up arrow.

Moves the cursor up from the denominator to the numerator of a fraction. Changes

**ALPHA**

cursor from lowercase to uppercase. Starting on a blank line, retypes previous lines sequentially beginning with most recent. In

**WINDOW**

mode, allows viewing of previous problems. In

**GRAPH**

mode, moves your view of the graph up. In

**TRACE**

mode, shows a more detailed step. If nothing else happens, then pressing the up arrow moves the cursor into an exponent.

Left arrow. Moves the cursor left.

When typing a square root, fraction or exponent structure, ensures that the cursor remains in that structure. In answer mode, decreases decimal precision. In

**WINDOW**

mode, shows more of the answer on the left. In

**GRAPH**

mode, moves your view of the graph to the left. In

**TRACE**

mode, goes back one step.

Right arrow. Moves the cursor right. Types a space when creating a mixed fraction. When typing a square root, fraction or exponent structure, exits that structure. In answer mode, increases decimal precision. In

**WINDOW**

mode, shows more of the answer on the right. In

**GRAPH**

mode, moves your view of the graph to the right. In

**TRACE**

mode, shows the next step.

Down arrow.

Moves the cursor down from the numerator to the denominator of a fraction. Changes

**ALPHA**

cursor from uppercase to lowercase. After using up arrow to retype previous lines and moving too far back, returns to retype more recent lines. In

**WINDOW**

mode, allows viewing of more recent problems. In

**GRAPH**

mode, moves your view of the graph down. In

**TRACE**

mode, shows less detail. If you just pressed the decimal point key, or if it would have no other effect, then pressing the down arrow moves the cursor into a subscript.

37

Q U I C K R E F E R E N C E

**,**

**2nd **

◄** **

**2nd **

►** **

Moves cursor to the beginning of the current line.

Moves cursor to the end of the current line.

Primary Function Keys

**2nd**

**MODE**

**DEL**

Activates the

**2nd**

cursor. Press again to deactivate the

**2nd**

cursor.

In answer mode, cycles between all possible ways to display an answer. In

**GRAPH**

mode, turns on and off labels that clash with the equation(s) graphed.

Deletes the character or symbol that the cursor is on. At the end of a line, works

**ALPHA**

**X,T,**

**Ө, n**

**STAT**

**MATH**

**APPS**

**PRGM**

**VARS**

**CLEAR**

*x*

**^**

**-1**

**SIN**

**COS**

**TAN**

*x*

**( **

**2 and )**

**LOG**

**LN**

**STO>**

as a backspace to delete last character or symbol typed.

When deleting a cube or higher root number, changes the structure to a square root. When on a blank line immediately following a problem divider, deletes the problem divider.

Activates the

**ALPHA**

cursor. Press again to deactivate the

**ALPHA**

cursor.

Retypes previously typed letters. Press once to retype the first letter you used in the current problem. Double-click to retype the second letter, press three times quickly for the third letter, and so on. After using your previously typed letters, or if you have not already typed a variable in the current problem, this key types

*x*

, then

*y*

, then

*z*

, then goes to the start of the alphabet at

*a*

, then

*b*

, and so on.

Not used.

Accesses the “Math Menu” to select math menu functions.

When not in Zoom Math, press to get a list of Apps. From the list of Apps, select

Zoom Math.

Not used.

Not used.

Erases the current line. If the current line was already empty, erases the whole screen. In answer mode, clears the answer, allowing you to edit the problem again.

In

**GRAPH**

mode, returns you to the solution screen. In

**TRACE**

mode, erases all solution steps and returns you to the original problem.

Raises an expression to the power of negative one. Double-click to raise an expression to the power of negative two, press three times quickly to raise an expression to the power of negative three, and so on.

Press to type sin

.

Press to type cos

.

Press to type tan

.

Press before entering a complicated exponent. Double-click to type a degrees symbol. In answer mode, displays answer in scientific notation.

Squares an expression. Double-click to cube an expression, press three times quickly to raise an expression to the power of four, and so on.

Types a comma.

Types parentheses.

Press to type log

and enable cursor to enter argument for log function.

Press to type ln

and enable cursor to enter argument for natural log function.

Not used.

38

Q U I C K R E F E R E N C E

Operation Keys

**÷ **

Creates a fraction. Double-click to type a division sign. If cursor is on fraction bar or division sign, toggles between the two. In answer mode, cycles between

**×**

**−**

**+**

**ENTER**

Numeric Keys

**0 **

through

** 9**

displaying answer as a fraction, mixed fraction, or quotient with remainder.

Types a multiplication sign.

Types a minus/negative sign. In

**GRAPH**

mode, zooms out your view of the graph.

Types a plus/positive sign. In

**GRAPH**

mode, zooms in your view of the graph.

Selects a menu choice. Moves to the next line when inputting a problem consisting of multiple lines within the solution screen. Solves a problem on the solution screen after input of the problem is complete. At the start of a blank line, inserts a problem divider if one is not already present. In

**GRAPH**

mode, returns you to the solution screen. In

**TRACE**

mode, shows all remaining steps including the solution.

**0 **

Types the desired digit. A digit immediately following a letter will become an exponent.

In

**GRAPH**

mode, centers your view of the graph to the origin.

In

**GRAPH**

mode, jumps your view of the graph to the respective quadrant.

**.**

**1 **

through

** 4 **

Types a decimal point. If you press

▼ next, then the decimal point disappears and the cursor moves into a subscript. In answer mode, displays answer as a decimal.

**(**

**−)**

Types a minus/negative sign.

2nd Function Keys

Any

**2nd**

function keys not listed here are not used within Zoom Math.

**2nd QUIT**

Exits Zoom Math.

**2nd INS**

**2nd A-LOCK**

Activates the insertion cursor. Press again to deactivate the insertion cursor.

Locks keyboard so that the

**ALPHA**

cursor does not change back to the normal cursor until you press

**ALPHA**

.

Press to type an angle symbol.

**2nd ANGLE**

**2nd SIN**

**2nd COS**

**2nd TAN**

Press to type csc.

Press to type sec.

Press to type cot.

**2nd **

**π**

**2nd **

**√**

**¯**

**2nd EE**

**2nd {**

**2nd }**

**2nd 10**

*x*

**2nd e**

*x*

**2nd OFF**

**2nd **

**÷ **

Types

π

(pi).

Creates an empty square root symbol. Double-click to create a cube root, press three times quickly to create a fourth root, and so on.

Press to type

×10

and enable cursor to enter exponent for scientific notation. In answer mode, displays answer in scientific notation.

Types the left side of an absolute value symbol.

Types the right side of an absolute value symbol.

Press to type

×10

and enable cursor to enter exponent for scientific notation. In answer mode, displays answer in scientific notation.

Press to type

*e*

and enable cursor to enter exponent.

Exits Zoom Math and turns calculator off.

Types a percent sign. In answer mode displays answer as a percentage.

39

Q U I C K R E F E R E N C E

**2nd **

**+ **

**2nd **

**8 **

Types a Σ sign with “i=1” below it, and puts the cursor above the Σ sign.

Types an ∞ sign.

**2nd ANS**

Types

**Ans**

, which represents the value of the answer to the previous problem.

ALPHA Function Keys

Any

**ALPHA**

function keys not listed here are not used within Zoom Math.

**ALPHA **

**ALPHA **

◄

◄

**Y= **

**ALPHA **

►

**ALPHA **

►

**Y= **

**ALPHA A**

through

**Z**

Types

<

(less than).

Types

≤

(less than or equal to).

Types

>

(greater than).

Types

≥

(greater than or equal to).

Types the desired letter.

**ALPHA E**

**ALPHA I**

**ALPHA **

**0 **

**( zero) **

**ALPHA **

**. **

Types

*e*

(the reserved constant representing the base of the natural log).

Types

*i*

(the reserved constant representing the square root of

-1

).

Types a space.

Types ! (factorial).

40

Q U I C K R E F E R E N C E

Chapter

7

## Technical Notes

## Program Limitations

You need at least 535 RAM free to start Zoom Math 400. If you run Zoom Math 400 with only

535-2582 RAM free, you will be warned that your memory is low. If you run Zoom Math 400 with low memory, the program’s performance may be substantially affected. For example, you may not be able to type a long problem, or scroll up to view or retype previous problems. If you have 2583 or more RAM free, Zoom Math 400 will run normally with no warnings.

Zoom Math 400 will run on the TI-Nspire with the 84-Plus keypad installed.

When you start Zoom Math 400, any Program named DELETEME is automatically deleted, and any AppVar named ZOOMTEMP is automatically deleted. Zoom Math 400 also reserves the right to delete any Program variable called DELME###, where ### stands for a 3-digit number—such as DELME001.

Zoom Math 400 cannot handle lists. If you input a function that yields a list answer, Zoom Math will not display that answer in most cases. The function rand is a special case. In the TI home screen, rand(5)

means a list of five random decimal numbers. But in Zoom Math 400, rand(5) means one random decimal number multiplied by five instead.

Zoom Math 400 cannot graph equations which include any of the following Math Menu functions: rand, randInt, randNorm, and randBin.

Zoom Math 400 cannot graph more than 16 equations at once.

Zoom Math 400 does not show every step when solving a rational equation or a radical equation.

Zoom Math 400 can solve rational equations and radical equations, but Zoom Math 400 does not show every step of these solutions. If you type a rational equation that has an extraneous solution, then Zoom Math 400 will show most of the steps of the solution, but at the very end of the problem, Zoom Math 400 will eliminate the extraneous solution without showing why. If you type a radical equation, then Zoom Math 400 will show every step until it is time to square both sides of the equation, and then Zoom Math will skip straight to the answer.

Zoom Math 400 sometimes assumes that radicands are positive.

**This can lead to a wrong **

**answer.** Zoom Math 400 is designed to handle Algebra 1 problems. Ordinarily, Algebra 1 problems do not involve negative radicands, so Zoom Math 400 generally assumes that radicands

41

T E C H N I C A L N O T E S are positive. For example, if you type

*x y*

, then Zoom Math 400 says

*x y*

=

*xy*

. This equation is usually correct, but if

*x*

and

*y*

are both negative, then it is incorrect.

Zoom Math 400 cannot store answers that are extremely long and complicated. If an answer is so complicated that it takes up several lines on the screen, then Zoom Math 400 may not be able to store the answer in

Ans

.

Zoom Math 400 cannot substitute out variables that are within Math Menu functions. Do not type a variable within a Math Menu function, except when the variable is required by the function.

For example, Zoom Math 400 can simplify fMin(2*x*, *x*, 0, 1)

because the second parameter of the fMin

function must be a variable. But Zoom Math 400 cannot simplify fMin(2*y*, *x*, 0, 1)

, since the value for

*y*

is not defined within this function.

Zoom Math 400 cannot calculate a Math Menu function that contains

Ans

. For example,

Zoom Math 400 cannot calculate round(Ans)

.

## Troubleshooting

Everything seems to be locked up. What should I do?

If you tell it to, Zoom Math will try to perform an extra-lengthy calculation. For example, if you enter the function randBin(1000000,0.5)

, you are essentially telling the calculator to flip a coin one million times. That would take a while. To cancel a long calculation, press

**ON**

. If that does not seem to be the issue, or you seem stuck in some other way, try pressing

**2nd QUIT**

to exit

Zoom Math. If that doesn’t work, you will have to remove the calculator’s batteries for a few seconds. When you turn the calculator back on, the calculator will restart.

CAUTION: Restarting the calculator will delete any information in RAM. If your calculator’s

RAM contains important data or programs you created, we recommend you either save a copy

(backup) of this information to your PC using appropriate TI tools, or refrain from using

Zoom Math. Few users keep data in RAM, and problems are unlikely, but caution is advised.

I think I found a mistake. What should I do?

If you think Zoom Math gave you a wrong answer, or you think something else isn’t working right, contact I.Q. Joe via our website, www.zoommath.com/contact.html

, and tell us what seems wrong.

I need help. What should I do?

First, check this user guide under the topic related to your question or problem area. Second, check our Frequently Asked Questions at www.zoommath.com/help.html

where we may have already answered your question. If you still need help, your next step is to contact I.Q. Joe via our website, www.zoommath.com/contact.html

, and we will gladly lend a hand.

42

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