Brief Users Guide for the
TI-89 Titanium
INDEX:
To facilitate lookup, the instructions are divided into
the following categories:
I.
Basic Information - What's my operating system version?, how much RAM do my
programs
take,
is my calc upgradeable?, adjusting brightness of display, friendly values using
TRACE,
navigating the APPS features, how to change settings, and how to obtain certain
symbols, what to
do if you have problems (see Section XII of this document.)
II. Basic Math – Math operations, square
roots, cube roots and others, fractions, logarithms
III. Special Expressions – Absolute Value, Greatest
Integer, etc., finding primes of a number
IV. Graphing and Evaluating Functions – Graphing, finding
zeros, finding intersections of graphs,
graphing inequalities, marking points on a graph, etc.
V. Special Functions – Greatest Integer, Absolute Value, Piecewise
Functions, Trig Functions,
etc.
Using [TABLE] to find points for graphing a parabola by hand.
VI. Polynomials -
Expand an expression, Simplifying an expression, Solving a polynomial, Solving
an inequality,
Simplifying and expression, Solving polynomials with degree higher than 2,
graphing polynomials from the
polynomial application,
VII. Calculus – Finding the derivative of a function, finding the
implicit derivative, finding the numerical derivative
of a function, determining the value of the derivative at a point on a graph,
drawing a tangent line to a graph,
finding the anti-derivative of a function, finding the integral of a function,
implicit derivative, finding the limit.
VIII. Matrices – Determinant,
Transpose, Row Operations, system of equations
IX. Differential Equations -
Draw slope fields, Draw slope fields and solution, Draw solution without
slope fields,
general and particular solution of an ODE, general and particular solution of a
second order diff. eq.
X. Sequences - Finding several terms of
a sequence, finding a specific term of a sequence,
summing sequences, cumulative sum of sequence, graphing a sequence.
XI. Complex Numbers -
Solving a polynomial with complex coefficients,
XII. Transferring Programs and Data – Transferring data or programs from
one calculator to
another.
XIII. Problems: How to reset
the calculator
RELEASE DATE:
8/28/07
DATE LAST REVISED: 7/28/08
Printer friendly page here.
© 2003 Frank Kizer
NOTE: Printing hints and
copying limits are at the end of this document.
GENERAL: All
keys have at least two functions and some have three. The default function for
a key is the white print on the key. When 2nd is pressed the
key function is as indicated in blue print on the panel
immediately above the key. When the ♦ key (the yellow key with the diamond
shape on it.) is pressed the functions in yellow print and activated. When
ALPHA is pressed, the function is the white label immediately above the key and,
in most cases, near the right end of the key. When APPS is pressed, the
applications screen will appear if it is turned on in the MODE screen..
I. BASIC
INFORMATION
1) Turning the calculator ON and OFF.
a) To turn on: Press the ON key.
b) To turn off: Press 2nd; then OFF (the second function
for the ON key.) If an error message is displayed
you will need to press the Shift key (the diamond symbol) and then press OFF.
2) Adjusting the contrast of the screen.
a) To make the screen display
darker: Hold down the ♦ key (the key below 2ND) and tap the + key.
b) To make the screen display lighter:
Hold down the ♦ key and tap the - key.
3) Finding your operating system version number.
a) From the APPS screen, press F1, 3.
As of 6/21/07, the TI Website listed the latest version of the OS as
Ver
3.10, 7-18-05.
4) Finding our how much free RAM I have.
a) Press 2nd; then MEM.
5) Is my calculator upgradeable? Yes, the
operating system is upgradable and applications may be added.
6)
Friendly Values on Graphs Using TRACE:
Many times
when you use the TRACE function, you will get an x-value such as 2.784532. If
you change the x-min
and x-max in the WINDOW function to be multiples of
7.9 and
the y-min and y-max to multiples of 3.8 , the displayed
values will be
"friendlier." That is, they will be integers or numbers with one or two decimal
places. You can always
set the values by hand, but the easiest method is to use
the ZDecimal function of ZOOM. Just press ZOOM; then
4, for ZDecimal.
It may be that the display is now partially off
the screen. If you want the entire graph on the screen, use the Zoom Out
function. To do that when in the graph mode, press F2; then 3, ENTER.
If you’re trying to find the value at a specific
point, a zero for example, and the cursor still does not fall on the x-axis,
you
could try different strategies such as ZBox, but I usually prefer to use the
zero function. To do that, press F5, 2.
That will set you up
for finding a root. Remember that any time you want to get back to the standard
window just
press F2, 6.
7. Using the APPS screen:
a) Press APPS to go to the screen that has
icons for all of the applications.
b) If the applications
are
not on the first screen, press the first letter of the title of the icon you want
to
select. For example, if you want
to select Matrices D, the first letter of the title Data/Matrices. For Lists
you
would press S for statistics.
c) Press 2ND, APPS to
toggle back and forth between the present screen and the previous APPS screen.
Note
that not all non-APPS screens are recalled by this method.
d) Another way to
organize the APPS functions is to place them in folders. As for myself, I
have placed the
six APPS that I use most often in the MATH folder. That way when I press
APPS, I can then press
F1,2, 4 and my most-often-used APPS will immediately be displayed on the screen.
To organize the APPS, do
this:
1) Press APPS, F1, right cursor arrow, 3. A dialog box with a list
of APPS will appear on the screen. Scroll
up or down the list with the cursor arrows and press the cursor right arrow to
select one of the APPS.
8. Clearing the Calculator Screen.
a) To clear the calculator home
screen: Press the F1, 8.
b) You can also use CLEAR to clear individual
entries on the home screen.
9. To move to another screen:
a) Press 2nd, QUIT
to go to the APPS screen from any screen.
10. Correcting errors or changing characters.
a) To replace a character at
the cursor position, just press the new
character.
b) To insert a character in the
position of the cursor, press 2nd, press
INS, and then press the key for
the desired character. Note that you will need to press 2ND, INS
again
to get out of the insert move and return to the strikeover mode.
c) To delete a character to the
right of the cursor, pulse ♦, DEL. You can also use the backspace key (←) to delete
characters to the left of the cursor.
11. Changing the MODE:
(Use the MODE for such things as changing from degrees to radians, displaying numbers as
powers of ten, using split screen, enabling
complex number calculations, turning off the APPS screen, changing the
language, and other similar things.)
a) Press the MODE key.
b) Use the arrow keys to move the cursor to the desired item.
c) Press the right cursor arrow
to bring up a menu; then press the number opposite the desired item on
the
menu..
d) Press ESC to return to the
last screen or 2ND, QUIT to return to the APPS screen.
12. Performing numerical calculations:
a) On the graphing calculator screen, the multiplication symbol will
appear
as * and the division symbol will appear as /.
b) Parentheses can be used to denote multiplication or as grouping symbols
to
clarify the order of
operations.
c) To enter an exponent use the ^ key for any exponent. Other functions are available by pressing,
2ND,
MATH; then press
the right cursor arrow and finally the number of the item on the pop-up menu
that
you desire.
d) Use the (-) key for negative numbers and the - key for subtraction.
II.
BASIC MATH
1. Raising a number to a power:
a) From the home screen, enter the number.
b) Press the ^ key
c) Enter the number for the power.
d) Press ENTER.
2. Finding the root of a number:
a) For square root, press 2nd; then the
square root symbol (multiply key).
b) Enter the number you want the square root of
and close the parentheses..
c) Press ENTER.
d) As an alternate method for the square root
and for any other root, do the following from the HOME screen:
1) Press,
♦, 9. The expression "root(" will be pasted to the screen.
2) Enter the number and root
according to the syntax root (number, root). For example, the cube root of
27 would be root(27,3). Be sure to close the parentheses.
3) Press ENTER and the answer will be displayed. .
NOTE: For those who have used other TI calculators that are very
forgiving about omitting closing
parentheses, be aware that parentheses must be closed on the TI-89.
3. Operations with fractions:
a) Use the divide symbol between the numerator
and denominator. Ex: ¼ is
entered as 1÷4.
b) Use the correct operator symbol (divide,
multiply, add, subtract) between
fractions.
c) Note: How to set the Exact/Approx mode is a
matter of preference for numerical calculations. If you put it
in Exact, you will get no decimals, and if you put it in Approximate,
multiplying two fractions will give
a decimal. So, I usually leave it in Auto. In that mode, if you want
a decimal answer, you must add
a decimal to one of the numbers. For example, 5/2 would become 5.0/2.
4. Logarithms:
a. To find the common log, press ♦; then 7.
b. Enter the number, press ), and then press
ENTER.
c. The natural logarithm is on the keyboard.
Just press 2ND, the X-key; close the parentheses and press ENTER.
III. SPECIAL
EXPRESSIONS:
1. To enter the symbols, equal to, not equal to, greater-than, less
than, greater than or equal to, and less than or
equal to:
a) Press the 2nd ; MATH,
8.
b) Enter the item number for the desired symbol.
2. To find the absolute value of a number:
a) Press 2ND, MATH, 1, 2.
b) Abs( will be pasted to the home
screen.
c) Enter your number, close the
parentheses.
d) Press ENTER.
3. Finding the greatest integer function of a number.
a) From the Home screen, press
the CATALOG key; then press the letter I.
b) Move the cursor down to int(
and press ENTER.
c) The expression int( will be
pasted to the Home screen.
d) Enter your number and close
the parentheses.
e) Press ENTER. (Note that
this also works for negative numbers.)
4. Finding the primes
of a number.
a. From
the home screen press F2, 2, and factor( will be pasted to the screen.
b. Enter the number you choose, close the
parentheses, and press ENTER to
display the results.
IV. GRAPHING &
EVALUATING FUNCTIONS:
1. Graphing a function.
a) Press ♦, F1 to display the "Y="
screen. All equations
must be in the slope-intercept form, y=mx+b,
before entry.
Note that only F1 and F2 are activated in this mode.
b) Enter the function(s) using the
appropriate keys to enter the
variable.
c) Press ♦, GRAPH to graph the function. (If you don’t see your
graph, press
TRACE and use the arrows to find the maximum or minimum value of your
function. Press ENTER
and the graph should appear.)
d) To leave the screen without
graphing, press Home.
e) Press CLEAR while the cursor is on the same line as the
function to erase the
function.
2. To obtain the standard size viewing window:
a) Press the F2 to go to the Zoom menu.
b) Press 6 to execute Z Standard.
3. To change the viewing window to a custom size:
a) Press ♦, WINDOW.
b) Use the cursor
keys to move the to the value to be
changed.
c) Enter the new value.
d) Press ♦, Graph
to see the new graph, or press ♦, F1 to return to the Y= screen.
e) ZSquare keeps the y-scale the same and adjust the x-scale so
that one unit on the x-axis equals one
unit on the y-axis.
f) ZDecimal makes each movement of the cursor equivalent to
one-tenth of a
unit.
g) ZInteger makes each movement of the cursor equivalent to one
unit.
4. Evaluating a function.
a) Press ♦, F1 and enter a
function, y1 for example.
b) Press ENTER.
c) At the Home screen, enter
y1(value) or for a series of values y1({value, value, value}). For
example, y1({1, 2, 3})
d) Press ENTER and the values will
be displayed.
5. To change or erase a function:
a) Press ♦, F1.
b) Use the arrow keys to move the cursor to the desired location
and make
changes by inserting, deleting, or changing the desired characters.
c) To erase a function, with the cursor on the same line as the
function, press the
CLEAR key.
6. To use the trace function:
a) From the Graph screen, press
F3.
b) Use the right and left arrow keys to move the cursor along
the graph. The
coordinates of the cursor location are shown
at the bottom of the screen.
c) If more than one graph is on the screen, you can press the up
or down arrows
to jump from
one graph to another.
d) To end the trace
operation, press ESC.
7. Finding the maximum and minimum points.
a) Enter the function and graph
it.
b) Press the F5. Press 3 for minimum or 4 for maximum.
c) Move the cursor to the left of the point
where a minimum or maximum appears to be and press ENTER.
d) Move the cursor to the right
of the point and press ENTER.
e) The coordinates of the maximum or minimum will appear at the bottom of the screen.
f) Press ESC to end this
operation.
8. Finding the value of a function at a given value of x.
a) Enter the function and the graph
it .
b) Press F5.
c) Press 1 to select value.
d) Enter the x-value and press
ENTER. The x- and y-values will appear at the bottom of the screen.
Press
ESC to terminate this operation.
9. To zoom in using a box.
a) Enter the function and graph
it.
b) Press the F2.
c) Press 1 to select ZBox.
d) Move the cursor above and to the left of the location you
want enlarged and
press ENTER.
e) Move the cursor below and to the right of the location you
want enlarged and
press ENTER.
f) The box is then enlarged to fill the screen.
Press F2, 6 to return to the Standard screen.
10. Finding the intersection point of two graphs.
a) Enter two functions on
separate "Y=" lines and press ♦, GRAPH to graph the equations. Equations must
be in slope-intercept form.
b) Press F5 to select the
list of operations
c) Press 5 to select
intersection. The cursor will appear on one of the curves. Move the
cursor
to a position so that the curves are clearly separated and to the left of the
first intersection point.
press ENTER. Press ENTER again if the cursor is on the second graph; then
press ENTER again
if the cursor is to the left of the intersection point.
d) The calculator will request the Upper Bound. Move the cursor to the right of the first
intersection
point but to the left of the second intersection point if there is more than one
intersection point.
e) Press ENTER and the
coordinates for that particular intersection point will appear at the bottom
of the screen. Press ESC to get out of this procedure.
f) If there is more
than one intersection point, evaluate the other points in the same way, except
the
cursor will initially be placed to the left of the point you are evaluating.
11. Solving an equation in one variable. (Also
known as finding the roots or x-axis intercepts.)
a) Enter the function and graph.
b) Press F5, 2..
c) Move the cursor to the
left of the first x-axis intercept and press ENTER.
d) Move the cursor to the right of that intercept and press
ENTER.
f) The coordinates for
the root (zero) will appear at the bottom of the screen.
g) Additional zeros
can be found by repeating this method for other x-axis intercepts.
12.
Finding coordinates to graph a parabola by hand.
a) Enter the graph
in your calculator as described above.
b) Next locate the
vertex by pressing F5, and pressing either 3 or 4, depending on
whether the vertex is a minimum or maximum for the parabola.
c) Move the cursor
slightly to the left of the vertex and press [ENTER].
d) Move the cursor
slightly to the right of the vertex and press [ENTER]. The x- and y-values
for the vertex will appear at the bottom of the screen
e) To find additional poinst, press [♦],[TABLE] and a table of (x,y)
values will appear. (You may want to set your
independent variable for Ask so that you can enter x-values of your own choosing.
If it is not set for Ask,
press
[♦], [TBLSET] and press the right arrow key and press 2 for "Ask," and a
table will appear if you started
the change from the table screen .
f) Enter two
more values for "x" in the table and the corresponding values for "y" will
appear.
g) Use these
coordinates and the symmetry property of a parabola to graph the parabola on a
sheet of paper. (NOTE: If the vertex is at an integer value, you can find
the vertex from the
table rather than using steps a through d to find the vertex.)
13.
Graphing Inequalities.
a) Write each
equation in the y =mx + b format and enter them into the "Y=" positions.
(Remember that you may need to change the direction of the inequality sign
if you have to
multiply by -1 during the rearranging of the equation.)
b) Select the
graph to be shaded and press 2ND, F1 (to select F6).
c)
Press 7 (Above) or 8 (Below) as appropriate and press ENTER. The shaded graph
will appear.
d) Press ♦,
GRAPH and the shaded graph will appear.
14.
Marking points on a graph.
A few students who
capture screens like to have marks on graphs. Although some would
consider this more
trouble than it's worth, I'll include it for those brave souls who feel they must
have them.
a)
First, if you are a little picky about having the marks line up exactly on the
graph, you
should press F2, 4 to select ZoomDec. Then graph your function and see if
the x-
and y-values that you are interested in appear on the screen. If not,
press F2 (Zoom), ALPHA, C to
select Set Factors. A dialog box will appear for setting xfact and yfact. Make the xFact and yFact
integers larger than 1. Press ENTER to save the new
zoom factors.
b) Go
to the Home screen to start the procedure. The syntax is PtOff x,y.
So, press
CATALOG, p, and cursor to PtOff.
c)
Press ENTER and PtOff will appear on the Home screen.
d)
Enter the x-coordinate, y-coordinate, and press ENTER. A barely visible,
for me, clear spot
will appear on the graph at the coordinates you selected.
e) To
erase all points, press 2ND, F1,1, ENTER.
V. SPECIAL FUNCTIONS
1. Changing from radian measure to the
degree mode:
a) Press the MODE key
b) Move the cursor to
Angle and press the right cursor arrow to select what you want.
c) Press ENTER to return
to the previous screen.
2. Graphing piecewise functions or functions on an
interval:
The piecewise expression has the form f1
if condition, else f2. Let's graph this:
| x for x> 0
f(x) = |
-x for x <0
a) Press ♦, F1 to
display the Y= screen.
b) Enter "when" as
as follows: Press CATALOG, w, select "when(" and press ENTER.
c) Press x; then
2ND, MATH, 8 (for Test), 4 to enter <.
d) Press 0, [,], x,
[,], (-), x). You should have "when(x< 0, x, -x)" on the in the
entry bar.
e) Press ♦, F3
(GRAPH) and the graph will be displayed.
VI. POLYNOMIALS
1. Expanding an Expression (can also be used for partial
fractions):
a) From the home
screen, press F2, 3. The expression expand( will be pasted to the home
screen.
b) Enter the number you want to expand, for
example (x²-1)/(x^3 +2x²), and close the parentheses. Your expression
should look like
this: expand((x^2-2)/(x^3+2x^2))
c) Press ENTER and the answer will be
displayed on the Home screen.
2.
Simplifying Algebraic Expressions:
1. Press F2, 7 to select propFrac(.
2. Enter your expression being careful to get the
parentheses correct. Example: profFrac((x^2 +3x +2)/(x+1)).
3. Press ENTER and the result will be displayed.
3.
Factor a Polynomial:
a) Press F2, to select factor(.
b) Enter your expression being sure to get the
parentheses correct. Example: factor(x^2 +5x +6).
c) Press ENTER and the result will be displayed.
4.
Solving a Quadratic Equation:
a) Press F2, 1 to select solve(.
b) Enter your equation. Example: solve(x^2+2x
+3=11, x). Note that you must have the variable, in this case x,
that you are finding the value
for.
c) Press ENTER and the answer will be displayed.
5.
Solving Inequalities:
a) Press F2, 1 to select solve(.
b) Enter you equation and close the parentheses.
Example: solve(x^2 +2>3, x). The > symbol is obtained
by pressing 2ND, and the
key below 2.
c) Press ENTER and the result will be displayed.
6.
Solving polynomials including those with degree higher than 2:
a) Press MODE, cursor to Complex Format and
press the right cursor arrow; then press 2 to select
rectangular unless you
specifically want polar.
b) Press ENTER, APPS, select the Polynomial
icon and press ENTER.
c) Press 3 for New. On the next screen, enter the degree of the
polynomial you are solving, for example 3, and
press ENTER.
d) Enter the coefficients for the terms starting
with the highest degree term. Press ENTER after each entry.
e) Press F5 and the solution will be displayed.
To enter a new polynomial, press ESC.
7.
Graphing a polynomial from the polynomial application:
a) Enter the polynomial coefficients according to
the item directly above.
1) Press F6 (that's
2ND, F1), 1, press the right arrow key.
2) Select Full for
Split Screen, select y1 for Store Poly To, and select whatever you want
for ZOOM. If you
don't have a choice, start with ZoomStd.
3) Press ENTER and
the graph will be displayed.
VII. CALCULUS
1. Finding the Derivative of an Function:
a) Press Home if not already at the Home
Screen.
b) Press F3, 1 to select
d( diferentiate.
c) Enter the function. For example, enter (x-y) 3/(x+y)
2 as follows:
d
( (, x, -, y, ), ^, 3, ÷, (,x, +, y, )^,2, comma, x) so that d((x-y)^3/((x+y)^2,
x) is displayed on the entry bar.
d) Press ENTER and the
result will be given.
2. Finding the Implicit Derivative:
I believe that this is a new capability that
does not appear on the TI-89 (not Titanium), but, at the end of this
discussion, I will suggest a method for finding the
derivative implicitly on the TI-89. Here is how to do it with
the TI-89 Titanium:
a) From the Home screen,
press F-3, ALPHA, D, and impDif( will be pasted to the
Home screen.
b) Enter information
according to this syntax: impDif(x^2 + y^2 = 5, x,y). Press ENTER
and the implicit
derivative, -x/y, (1st derivative) will be displayed. If you
want the second, or even the third derivative, you
can add that after the dependent variable, y, as in the following:
impDif(x^2 + y^2 = 5, x,y,2). The 2 is for the
2nd derivative. For the first derivative, omit the number.
c) Press ENTER and the
derivative will be displayed.
Now, how to do this with the TI-89 (not Titanium):
Remember some time back in the past you
learned that if z is a function of x and y, then you can write the
relationship below:
dy/dx = -(∂z/∂x)/(∂z/∂y) (Eq 1)
So, let's just take the derivative treating
y as a constant; then the derivative treating x as a constant.
Then we'll just plug them into Eq 1 above.
We may need to do a little simplification, but that should get
us close. Don't forget the
negative sign in Eq. 1.
So, here are the steps to do x2
+ y2 =5:
a) Press 2ND, MATH,
ALPHA, 1 and d( will be pasted to the home screen.
b) Enter terms so that
your entry looks like this: d(x^2+y^2 = 5, x).
c) Press ENTER and the
answer, -x, will be displayed. That's the numerator.
d) Replace the "x"
for the variable, the last x, with
"y."
e) Press ENTER and -y
will be displayed. That's the denominator.
g) Now, plug those into
Eq 1 and you'll have dy/dx= -(-x/-y) = -x/y, which is the same answer we
obtained
with the TI-89 Titanium. Of course, you could define a variable, but I'll
leave that to the calculator geeks.
3. Finding the numerical derivative of a function:
a) From the Home screen, press the F3, ALPHA, A. .
The expression nDeriv( will be displayed
b) Enter the expression you want to
find the derivative of. For example, d(x^2)dx would be nDeriv(x^2,x).
c) Press ENTER and the result will be displayed.
4. Determining the value of the derivative from
points on a graph:
a) First enter the function and graph it. The press the F5, 6,1. A
flashing cursor will be displayed on the graph.
b) Move the cursor to the point on the
graph where you want to find the derivative and press
ENTER.
c) The value of the derivative at that point will be displayed.
5. Drawing a tangent line at a point.
a) Enter the function and graph
it.
b) From the graphing
screen, press F5, ALPHA, A.
c) Move the flashing
cursor that appears to the point where you want the tangent and press ENTER.
d) The tangent line will
be drawn at that point.
e) To clear the
tangent line, press ESC, F4.
6. Finding the Antiderivative of a Function:
a) From the Home screen,
press 2ND, ∫, (the
number 7 key).
b) Enter the expression
of interest. For example ∫ x^2 dx would be ∫ (x^2, x)
e) Press the ENTER and
the antiderivative will be displayed.
7. Calculating the value of a definite integral:
a) Graph the function of
interest and press F5, 7.
b) Move the flashing
cursor to the lower limit you desire and press ENTER; then move the
cursor to the upper limit you desire and press ENTER
c) The area will be
shaded and the value of the are will be displayed.
8. Finding the limit of a function:
a) From the Home screen, press
F3, 3 to paste limit( to the screen.
b) The syntax is "limit( expression,
var, point, direction)," where direction from the left is -1 and from
right is 1.
Lets do the limit of 1/x as x approaches 5.
c) Enter information so that you have
"limit(1/x, x, 5).
d) Press ENTER and the answer, .2
will appear.
e) To find the limit of the same
expression as x →∞, erase 5 and
press ♦, CATALOG to paste
∞ to the
screen.
f) Make sure the
parentheses are closed; then press ENTER and the answer,
0, will be displayed.
VIII. MATRICES:
General: When it comes to doing matrices, there are different
ways of setting them up and editing them,
but I am going to stick with one way. If you want to try another, read
your user manual (good luck.). I'm first
going to tell you how to set up a matrix using the Data/Matrix editor; then I'll
show you how to edit a matrix
that has already been set up. Finally, I will tell you how a teacher might
set up his calculator to save lecture
time with the details.
1) Entering and Editing a Matrix:
A) Entering a Matrix:
a) Press
[APPS] if you're not already at the APPS menu; then select the Data/Matrix icon
and press
[ENTER]. Press 3 to select New. Note: When you go to the APPS
screen, the Data/Matrix icon
may not be displayed on the screen. To display a group which has the
Data/Matrix icon, press D.
b) With the cursor
opposite Type, press the right cursor arrow and press 2 for Matrix.
c) Move the cursor down
to the space for Variable and type in whatever variable you want. Type in
whatever
unrestricted variable you choose. If you intend to retain this
matrix, I suggest you not use the
variables a-z because sometimes it is convenient to clear all of these at the
same time.
d) After you have entered
the variable move down and enter the number of rows and columns; then
press ENTER and the matrix table will be displayed.
e) You can now either
enter data or press Home and edit the matrix when you need it. To enter data, enter
each value
and press ENTER. The cursor will automatically move to the next position
for the next entry.
f) After you are
finished, press Home to go to the home screen.
B) Editing a Matrix:
a) Press [APPS] if you're not already at the
APPS menu; then select the Data/Matrix icon and press
[ENTER]. Press 2 to select Open
b)
Press the right cursor arrow and press 2 to select Matrix; then move the cursor
down to Variable, press
the right arrow, select the matrix you want and press ENTER, ENTER. The
matrix will be displayed for
editing.
c)
Enter data and press ENTER after each entry.
d)
After you've entered all of the data, press Home to go to the home screen for
matrix operations.
Note: If you want to display a matrix from the home screen you can
Press 2ND, VAR-LINK (the minus key),
F2, cursor to Var Type, press right cursor, 4, ENTER. Then highlight the
matrix you want and press
ENTER. The matrix name will be displayed. Press ENTER and the
matrix will be displayed on the Home
Home screen.
C) Comments:
a) As I go through the operations you will notice that I have variable
names for my matrices that may seem
to you to waste memory. I have done that because I mostly teach others how
to do matrices, and my
method save time for me. I have chosen to store permanently
matrices of several different dimensions
and to give them variable names so that I can immediately identify
what dimensions they have. For
example, Matrix m134 would be the first of the 3x4 matrices;
m234 would be the second.
2) Multiplying two matrices [m133] * [m233]:
a) Enter the data into matrices [m133] and [m233]
according to "Editing a Matrix" above, and press Home
to go to the home screen.
b) From the home
screen, enter the name of the matrix, e.g., m133.
c)
Press x (the multiply sign) and enter the name of the
second matrix, e.g., m233.
d) Press ENTER to perform the multiplication step.
e) Remember that the numbers of columns in [m133] must equal
the number of
rows in [m233] or you will get a dimension error.
3) Doing other matrix math:
a) Press 2nd, MATH, 4. On a pop-up list you
will see a list of operations that you can do. To find the
transpose, use T;
to find the determinant, use det(, to find the reduced
row-echelon form use rref(, and
so on with the other operations. .
b) After you select the operation you want, press ENTER
and the operation will be pasted to the home screen..
c) Enter the
variable name of the matrix you want and close the parentheses.
d) Press ENTER again to get your answer.
NOTE: You can do any of the elementary row operations,
swap rows, multiply a row by a constant, add two rows,
multiply one row by a constant and add it to another row, by pressing 2ND, MATH,
4, ALPHA, J, pressing the right arrow
key and selecting the
operation you want to do. They are very
useful for doing the arithmetic for Gauss or Gauss-Jordan
elimination, but
considerable time is required to get the hang of doing row operations. So, since most students don’t
take the time
to use those functions, I’m not going to include them. Instead,
I’ll give you my Website as a reference for doing those operations if
you want
to do them. If there are enough request, I will include that.
4) Doing rref and ref:
Since rref and ref are used extensively in
our college, I'm going to include them as separate items.
a) First enter the data
in your matrix (First set up the matrix if you do not already have one set up.)
as outlined above and press Home to go to the home screen.
b) Press 2ND, MATH, 4;
then 3 for ref( and 4 for rref(. The chosen operation will be pasted to
the
Home screen.
c) Enter the name of the
matrix where you entered your data, e.g., m134, and close the parentheses.
d) Press ENTER and the
new matrix will be displayed on the home screen. Of course, to clear the
screen,
press
F1, 8.
5)
Solving a system of linear equations:
Let's take the following set of simple equations:
3x -3y = -2
2x +y = 1
Entering Data in the matrix:
a) Press [APPS] if you're not already at the APPS menu; then
select the Data/Matrix icon and press
[ENTER]. Press 2 to select Open. (Note: If you do not have a 2x2
matrix stored in your calculator,
follow "Entering a Matrix" above to set up your matrix.
b)
On the dialog box that appears, press the right cursor arrow and press 2 to select Matrix; then move the
cursor down to
Variable, press the right arrow, select the matrix you want and press ENTER,
ENTER.
The matrix will be displayed.
c) Enter each value of the matrix and press ENTER after
each value. Enter only the coefficients of the
variables and the constants. Do NOT enter variables, or plus signs, but do
enter negative signs (not minus
signs.). Enter the numbers 3, -3, -2, 2, 1, 1 and press ENTER after each number.
d) When your
are finished entering data, press Home to go to the home screen.
Note: If you want to display a matrix from the home
screen you can Press 2ND, VVAR-LINK (the minus key),
F2, cursor to Var Type, press right cursor, 4, ENTER. Then highlight the
matrix you want and press
ENTER. The matrix name will be displayed. Press ENTER to display the
matrix.
Solving the system of equations using the rref
operation:
e) Press 2ND, MATH, 4; then press 4 for rref(. The chosen operation will be pasted to the
Home screen.
f)
Enter the name of the matrix where you entered your data, e.g., m134, and
close the parentheses.
g) Press
ENTER and the new matrix will be displayed on the home screen. Of course,
to clear the screen,
press F1, 8.
IX.
DIFFERENTIAL EQUATIONS:
1) Draw the slope
field for a differential equation:
Let's
take the very simple example y' = 2x .