Texas Instruments TI-83 - Plus Graphing Calculator User manual

Chapter 1
Coping with the Basics
In This Chapter
䊳Turning the calculator on and off
䊳Using the keyboard
䊳Using the menus
䊳Setting the mode of the calculator
䊳Using the Catalog
The TI-83 and TI-84 graphing calculators are loaded with
many useful features. With them, you can construct and
investigate geometric figures. You can graph and investigate
functions, parametric equations, polar equations, and
sequences. You can use them to analyze statistical data and to
manipulate matrices. You can even use them to calculate
mortgage payments.
But if you’ve never used a graphing calculator before, you
may at first find it a bit intimidating. After all, it contains
about two dozen menus, many of which contain three or four
submenus. But it’s really not that hard to get used to using the
calculator. After you get familiar with what the calculator is
capable of doing, finding the menu that houses the command
you need is quite easy. And you have this book to help you
along the way.
When to Change the Batteries
The convenience of battery power has a traditional downside:
What if the batteries run out of juice at a crucial moment, say
during a final exam? Fortunately, the calculator gives you some
leeway. When your batteries are low, the calculator displays a
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“Your batteries are low” warning message. After you see this
message for the first time, the calculator should, according to
the manufacturer, continue to function just fine for at least one
week. There is one exception: If you attempt to download an
application when the batteries are low, the calculator displays
a “Batteries are low — Change is required” warning message
and refuses to download the application until after you’ve
changed the batteries.
Because you’ve likely put batteries into countless toys, you
should have no trouble opening the cover on the back of the
calculator and popping in four AAA batteries. Above the AAA
battery chamber is a panel that opens to the compartment
containing the backup battery. The type of battery housed in
this compartment is indicated on the lid of the panel. The
manufacturer recommends that you replace this battery
every three or four years. So mark your calendar!
Turning the Calculator On and Off
Press …to turn the calculator on. To turn the calculator off,
press y, and then press …. These keys are in the left column
of the keyboard. The …key is at the bottom of the column,
and the ykey is the second key from the top of this column.
To prolong the life of the batteries, the calculator automati-
cally turns itself off after five minutes of inactivity. But don’t
worry — when you press …, all your work will appear on
the calculator just as you left it before the calculator turned
itself off.
In some types of light, the screen can be hard to see. To
increase the contrast, press and release yand then hold
down }until you have the desired contrast. To decrease the
contrast, press yand hold Ü.
Using the Keyboard
The row of keys under the calculator screen contains the keys
you use when graphing. The next three rows, for the most
part, contain editing keys, menu keys, and arrow keys. The
arrow keys (~|}Ü) control the movement of the cursor.
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The remaining rows contain, among other things, the keys you
typically find on a scientific calculator.
Keys on the calculator are never pressed simultaneously. In
this book, an instruction such as y… indicates that you
should first press yand then press ….
Accessing the functions
in blue and yellow
Above and to the left of most keys is a secondary key func-
tion. These functions are yellow on the TI-83 Plus calculator
and blue on the TI-84. To access that function, first press y
and then press the key. For example, πis above the õkey, so
to use πin an expression, press yand then press õ.
Because hunting for the function can be tedious, in this book I
use only the actual keystrokes. For example, I will make state-
ments like, “πis entered into the calculator by pressing
yõ.” Most other books would state, “πis entered into the
calculator by pressing y[π].”
When the ykey is active and the calculator is waiting for
you to press the next key, the blinking $cursor symbol is
replaced with the nsymbol.
Using the Ékey
to write words
Above and to the right of most keys is a letter written in
green. To access these letters, first press Éand then
press the key. For example, because the letter O is in green
above the ¨key, to enter this letter, press Éand then
press ¨.
Because hunting for letters on the calculator can be tedious, I
tell you the exact keystrokes needed to create them. For exam-
ple, if I want you to enter the letter O, I say, “Press ɨ to
enter the letter O.” Most other books would say “Press É
[O]” and leave it up to you to figure out where that letter is on
the calculator.
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You must press Ébefore entering each letter. However,
if you want to enter many letters, first press yÉ to
lock the calculator in Alpha mode. Then all you have to do is
press the keys for the various letters. When you’re finished,
press Éto take the calculator out of Alpha mode. For
example, to enter the word TEST into the calculator, press
yÉWòµW and then press Éto tell the calcula-
tor that you’re no longer entering letters.
When the calculator is in Alpha mode, the blinking $cursor
symbol is replaced with the ÿsymbol. This symbol indicates
that the next key you press will insert the green letter above
that key. To take the calculator out of Alpha mode, press
É.
Using the Õkey
The Õkey is used to evaluate expressions and to execute
commands. After you have, for example, entered an arithmetic
expression (such as 5 + 4), press Õto evaluate that expres-
sion. In this context, the Õkey functions as the equal sign.
Entering arithmetic expressions is explained in Chapter 2.
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Keys to remember
The following keystrokes are
invaluable:
⻬yz: This is the equivalent of
the Escape key on a computer. It
gets you out of whatever you’re
doing (or have finished doing) and
returns you to the Home screen.
The Home screen is where the
action takes place. This is where
you execute commands and eval-
uate expressions.
⻬Õ:This key is used to exe-
cute commands and to evaluate
expressions. When evaluating
expressions, it’s the equivalent of
the equal sign.
⻬ë: This is the “erase” key. If
you’re entering something into the
calculator and change your mind,
press this key. If you want to erase
the contents of the Home screen,
repeatedly press this key until the
Home screen is blank.
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Using the Ñkey
Ñis the key you use to enter the variable in the definition
of a function, a parametric equation, a polar equation, or a
sequence. In Function mode, this key produces the variable X. In
Parametric mode it produces the variable T; and in Polar and
Sequence modes it produces the variables θand n, respectively.
Setting the mode is explained later in this chapter.
Using the arrow keys
The arrow keys (~, |, }, and Ü) control the movement of
the cursor. These keys are in a circular pattern in the upper-
right corner of the keyboard. As expected, ~moves the
cursor to the right, |moves it to the left, and so on. When I
want you to use the arrow keys — but not in any specific
order — I refer to them all together, as in “Use ~|}Ü to
place the cursor on the entry.”
What Is the Home Screen?
The Home screen is the screen that appears on the calculator
when you first turn it on. This is the screen where most of the
action takes place as you use the calculator — it’s where you
evaluate expressions and execute commands. This is also the
screen you usually return to after you’ve completed a task
such as entering a matrix in the Matrix editor or entering data
in the Stat List editor.
Press yz to return to the Home screen from any other
screen. This combination of keystrokes, yz, is the equiv-
alent of the Escape key on a computer. It always takes you
back to the Home screen.
If you want to clear the contents of the Home screen, repeat-
edly press ëuntil the Home screen is blank.
The Busy Indicator
If you see a moving vertical line in the upper-right corner of
the screen, this indicates that the calculator is busy graphing
a function, evaluating an expression, or executing a command.
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If it’s taking too long for the calculator to graph a function,
evaluate an expression, or execute a command, and you want
to abort the process, press …. If you’re then confronted with
a menu that asks you to select either Quit or Goto, select Quit
to abort the process.
Editing Entries
The calculator offers four ways to edit an entry:
⻬Deleting the entire entry:
Use ~|}Ü to place the cursor anywhere in the entry
and then press ëto delete the entry.
⻬Erasing part of an entry:
To erase a single character, use ~|}Ü to place the
cursor on the character you want to delete and then
press {to delete that character.
⻬Inserting characters:
Because “typing over” is the default mode, to insert char-
acters you must first press y{ to enter Insert mode.
When you insert characters, the inserted characters are
placed to the left of the cursor. For example, if you want
to insert CD between B and E in the word ABEF, you
would place the cursor on E to make the insertion.
To insert characters, use ~|}Ü to place the cursor at
the location of the desired insertion, press y{, and
then key in the characters you want to insert. When
you’re finished inserting characters, press one of the
arrow keys to take the calculator out of Insert mode.
⻬Keying over existing characters:
“Type over” is the default mode of the calculator. So if
you want to overtype existing characters, just use
~|}Ü to put the cursor where you want to start, and
then use the keyboard to enter new characters.
On the Home screen, the calculator doesn’t allow you to
directly edit an already-evaluated expression or an already-
executed command. But you can recall that expression or
command if it was the last entry you made in the calculator —
and when it’s recalled, you can edit it. To recall the last
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expression or command, press yÕ. This makes the cal-
culator paste a copy of the desired expression or command
on the Home screen so you can edit it.
Using Menus
Most functions and commands you use are found in the
menus housed in the calculator — and just about every chap-
ter in this book refers to them. This section is designed to
give you an overview of how to find and select menu items.
Accessing a menu
Each menu has its own key or key combination. For example,
to access the Math menu, press ç; to access the Test
menu, press yç. An example of a menu appears in the
first picture in Figure 1-1. This is a picture of the Math menu.
Some menus, such as the Math menu, contain submenus. This
is also illustrated in the first picture in Figure 1-1. This picture
shows that the submenus in the Math menu are MATH, NUM,
CPX, and PRB (Math, Number, Complex, and Probability).
Repeatedly press ~to view the items on the other submenus;
repeatedly press |to return to the Math MATH submenu. This
is illustrated in the second and third pictures in Figure 1-1.
Figure 1-1: Submenus of the Math menu.
Scrolling a menu
After the number 7 in the first two pictures in Figure 1-1, a
down arrow indicates that more items are available in the menu
than appear on-screen. There’s no down arrow after the 7 in the
third picture in Figure 1-1 because that menu has exactly seven
items.
Math MATH menu Math NUM menu Math PRB menu
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To see menu items that don’t appear on-screen, repeatedly
press Ü. To get quickly to the bottom of a menu from the top
of the menu, press }. Similarly, to quickly get from the
bottom to the top, press Ü.
Selecting menu items
To select a menu item from a menu, key in the number (or
letter) of the item or use Üto highlight the number (or letter)
of the item and then press Õ.
Some menus, such as the Mode menu that is pictured in
Figure 1-2, require that you select an item from a list of items
by highlighting that item. The list of items usually appears in a
single row and the calculator requires that one item in each
row be highlighted. To highlight an item, use ~|}Ü to place
the cursor on the item and then press Õto highlight the
item. The selections on the Mode menu are described in the
next section.
Setting the Mode
The Mode menu, which is accessed by pressing z, is the
most important menu on the calculator; it tells the calculator
how you want numbers and graphs to be displayed. The Mode
menu is pictured in Figure 1-2.
Figure 1-2: The Mode and Clock menus.
One item in each row of this menu must be selected. Here are
your choices:
⻬Normal, Sci, or Eng:
This setting controls how numbers are displayed on the
calculator. In Normal mode, the calculator displays
Mode menu Clock menu
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numbers in the usual numeric fashion that you used in
elementary school — provided it can display it using no
more than ten digits. If the number requires more than
ten digits, the calculator displays it using scientific
notation.
In Scientific (Sci) mode, numbers are displayed using sci-
entific notation; and in Engineering (Eng) mode, numbers
are displayed in engineering notation. These three modes
are illustrated in Figure 1-3. In this figure, the first answer
is displayed in normal notation, the second in scientific
notation, and the third in engineering notation.
In scientific and engineering notation, the calculator uses
Ento denote multiplication by 10n.
Figure 1-3: Normal, scientific, and engineering notations.
⻬Float 0123456789:
Select Float if you want the calculator to display as many
digits as possible. Select 0if you want all numbers rounded
to an integer. If you’re dealing with money, select 2so
that all numbers will be rounded to two decimal places.
Selecting 5rounds all numbers to five decimal places, and,
well, you get the idea.
⻬Radian or Degree:
If you select Radian, all angles entered in the calculator
are interpreted as being in radian measure; all angular
answers given by the calculator will also be in radian
measure. Similarly, if you select Degree, any angle you
enter must be in degree measure, and any angular
answer given by the calculator is also in degree measure.
⻬Func, Par, Pol, or Seq:
This setting tells the calculator what type of functions you
plan to graph. Select Func to graph plain old vanilla func-
tions, y= f(x). Select Par to graph parametric equations;
Pol to graph polar equations; and Seq to graph sequences.
(Sequences are also called iterative equations.)
Engineering
Scientific
Normal
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⻬Connected or Dot:
In Dot mode, the calculator produces a graph by plotting
only the points it calculates. In Connected mode, the cal-
culator joins consecutively plotted points with a line.
My recommendation is to select the Connected mode
because each of the graphing options (Func, Par, Pol,
and Seq) allows you to select a graphing style, one of
which is the dot style.
⻬Sequential or Simul:
In Sequential mode, the calculator completes the graph
of one function before it graphs the next function. In
Simultaneous (Simul) mode, the calculator graphs all
functions at the same time. It does so by plotting the
values of all functions for one value of the independent
variable, and then plotting the values of all functions for
the next value of the independent variable.
Simul mode is useful if you want to see whether two
functions intersect at the same value of the independent
variable. You have to watch the functions as they are
graphed in order to see if this happens.
⻬Real, a + bi, or re^θi:
If you’re dealing with only real numbers, select the Real
mode. If you’re dealing with complex numbers, select a +
biif you want the complex numbers displayed in rectan-
gular form. If you want complex numbers displayed in
polar form, select the re^θimode.
⻬Full, Horiz, or G-T:
The Full screen mode displays the screen as you see it
when you turn the calculator on. The other screen modes
are split-screen modes. The Horiz mode is for when you
want to display a graph and the Y= editor or the Home
screen at the same time. Use the G-T mode when you want
to display a graph and a table at the same time. (The split-
screen modes are explained in detail in Chapters 8 and 9.)
⻬Set Clock:
This is where you set the clock on the calculator. To do
this, use the arrow keys to place the cursor on the SET
CLOCK option and press Õ. You see the second pic-
ture in Figure 1-2. You use the arrow keys to move from
item to item. To select items in the first, fifth, and eighth
rows, place the cursor on the desired item and press
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Õto highlight that item. To enter numbers in the
other options, edit the existing number or press ë
and use the keypad to enter a new number. When you are
finished setting the clock, save your settings by placing
the cursor on SAVE and pressing Õ.
If you’re planning on graphing trigonometric functions, put
the calculator in Radian mode. Reason: Most trig functions are
graphed for -2π≤x≤2π. That is approximately –6.28 ≤x≤6.28.
That’s not a bad value for the limits on the x-axis. But if you
graph in Degree mode, you would need –360 ≤x≤360 for the
limits on the x-axis. This is doable . . . but trust me, it’s easier
to graph in Radian mode.
If your calculator is in Radian mode and you want to enter an
angle in degrees, Chapter 3 tells you how to do so without
resetting the mode.
Using the Catalog
The calculator’s Catalog houses every command and function
used by the calculator. However, it’s easier to use the keyboard
and the menus to access these commands and functions than it
is to use the Catalog. There are several exceptions; for example,
the hyperbolic functions are found only in the Catalog. If you
have to use the Catalog, here’s how to do it:
1. If necessary, use ~|}Ü to place the cursor at the
location where you want to insert a command or
function found in the Catalog.
The command or function is usually inserted on the
Home screen, or in the Y= editor when you’re defining
a function you plan to graph.
2. Press y) to enter the Catalog.
This is illustrated in the first picture in Figure 1-4.
3. Enter the first letter in the name of the command or
function.
Notice that the calculator is already in Alpha mode, as is
indicated by the ÿin the upper-right part of the screen.
To enter the letter, all you have to do is press the key
corresponding to that letter. For example, if you’re using
the Catalog to access the hyperbolic function tanh,
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press Wbecause the letter Tis written in green above
this key. This is illustrated in the second picture in
Figure 1-4.
4. Repeatedly press Üto move the indicator to the
desired command or function.
5. Press Õto select the command or function.
This is illustrated in the third picture in Figure 1-4.
After pressing Õ, the command or function is
inserted at the cursor location.
Figure 1-4: Steps for using the Catalog.
Press y ) Enter first letter Select item
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