1) How
to navigate around in the various modes of the
calculator?
The Casio graphing calculators are menu driven calculators similar to
a computer. To do any type operations, you must first select the
mode appropriate to that operation by pressing MENU, selecting the
appropriate icon, and pressing EXE. Submenus are available
either by default or by pressing the SHIFT key. An item from the
submenu is then selected by pressing the F-key (F1 through F6) that aligns
vertically with the desired operation. You may backstep through the menu levels
by pressing EXIT or go directly to the highest level by pressing SHIFT,
QUIT.
2) Some basic
modes
explained.
The icon for normal arithmetic, roots, powers, and trigonometry
functions is RUN. Most of the other icons are
obvious. Possible excepts may be that to do a
table of values for a function, you must use the TABLE icon; to do
financial functions use the TVM, and to do a system of equations (similar to
Matrix rref on the TI-83 Plus) you must use the EQUA icon.
3) Isn't there
a way to edit entries on the CFX-9850 the way my friends use ENTRY on the
TI-83 Plus?
As a matter of fact,
yes. Although it's not quite like the TI-83 Plus. Let's
say you've entered several calculations and you want to edit the last
one. Press the left cursor if want to start editing at the end of
the expression or the right cursor if you want to start at the
beginning.
Now, suppose you have
entered three expressions, and you want to go back and edit the first one.
a) Press
AC. All of the expressions are cleared from the screen, but don't
panic. They are all stored in
memory.
b) Press
the up arrow and the expressions and will appear in inverse sequence
as the up-arrow is
pressed
sequentially.
====================
II. GRAPHING:
1)
How do I graph an equation of the form 3x2 + 2x -1?
a) With the calculator on, press MENU, select the GRAPH icon
using the arrow keys and press EXE. The Y= menu will
then be
displayed.
b) Press 3; then the X,0,T key to enter x; the the x2
key; +, the 2 key; the X,0,T key again; the subtract key (not the minus);
and finally the 1 key. Press EXE to store the
equation.
c) Now press F6, the F-key corresponding to DRAW, to graph the function.
2) How do I set the
window?
Since most people at our school will be using the TI-83 Plus or TI-84
Plus, so I'm going to suggest that you set up the
window that is listed
as "Standard" on the TI.
a) When in the draw graph or equation entry submenu of the
calculator, press SHIFT, V-Window. Set X-min at -10, X-
max at 10 and
Y-min and max at -10 and 10 respectively. Set both scales at 1.
b) Press EXIT to go back to the screen you were at before you
started setting the window.
3) How do I find some x-y
values for a function to use in plotting the function by hand?
a) You must press MENU, select the TABLE icon, and press EXE.
The display will look like the equation entry screen
except that TABL will
have replaced DRAW.
b) If you haven't already entered the equation, enter the equation
as explained above and press the F6 key for TABL. A
table of x and y
values will be displayed. If you want more values, see the
next explanation.
4) My CFX-9850
won't scroll past certain numbers in a table. How can I fix
that?
Students often notice this when they're working with someone who has a
TI-83 Plus, which will scroll past the limits set
in the table. The
CFX-9850 won't do that. One way to compensate for that is to set the
RANGE very wide, say -15 and
15 and just leave it there. To do
that, just press F5 for RANG when you're in the table Y= mode; then enter
-15 for Start
and 15 for End. When you're in the graphing mode, you
might find it convenient to just use the TRACE function. Do
that as
follows:
a) Press
SHIFT, ZOOM and press F6 if INTG is not displayed.
b) Press F4 (INTEG);
then press SHIFT, F1(TRACE), and you can use the cursor to scroll through
different x-values.
5) When I enter an
equation with large coefficients, I often can't find the graph on my Casio
CFX-9850Plus. How do I
find
it?
Press SHIFT, ZOOM, F5 (AUTO)
6) How do I graph a
piecewise function on a Casio CFX-9850BG
Plus?
Doing this on the Casio is very
straightforward.
Let's say we have this piecewise function to
graph:
3x-2 {
-5<x<0
x +1 {
0<x<5
Then in the Y=
graphing list, type this:
Y1= 3x-1, [-5,0]
Y2=x+1, [0,
5]
Press [F6] and that's all
there is to it.
(7) How do I graph a circle on
the
CFX-9850Plus?
a) Go to the MENU, select CONICS, and press
EXE.
b) Scroll down to the diagram of a circle and press
EXE.
c) Enter the x-coordinate of the center for H; y-coordinate for K;
and the radius for
R.
d) Press F6,
DRAW.
Notice that your circle will not appear circular unless you have the
proper window setup. To get the proper setup, press
SHIFT, ZOOM,
F6,F2(SQR). If the circle is too small, press SHIFT,
ZOOM,F5(AUTO).
(8) How do I draw a circle on a
graph?
Well, it's easy to graph a circle with the CFX-9850Plus, but here's
how to SKETCH
one.
a) From the graph screen, press SHIFT, F4
(SKETCH).
b) Press F6; then
F3(Crcl).
c) Move the cursor to the point where you want to center of the
circle to appear and press
EXE..
d) Now move the cursor out to the length of the radius and press
EXE. A circle will appear.
To
clear sketches, press SHIFT; SKETCH; F1.
(9) How do I graph and inequality on the
CFX-9850+ and do the
shading?
a)
First, solve the inequalities for y. (Be sure to solve the inequalities,
not the equations. )
b)
Select the GRAPH icon and press EXE. If a graph is shown, press F6
to go to the Y=
Screen.
c) Press
F3 (Type), and then F6 to go to the inequalities.
d) Select the
applicable inequality and press its corresponding "F" key.
e) Enter the
inequality expression and press EXE to
store.
f) Press F6,
DRAW, to graph.
(10) How do I set up the domain for a function on a
CFX-9850Plus?
Setting the domain is very straight forward. Say, you want to graph
3x-1 from -5 to 0. Enter this in variable Y1 in
1) 3x-1,
[-5,0]. Then press [EXE], F6. That's all there is to it.
11) Is there a
special operation for graphing the inverse of a function?
Actually, what you
can do is "sketch" the inverse, mostly to allow you to get an idea of what
the inverse looks like.
None of the operations
such as Trace, G-Solv, or Table will work with the inverse sketch.
To sketch the inverse do the
following:
a) From
the graph screen press F4 (Sketch).
b)
Press F4 again and the inverse will be sketched.
12) Is
there a more accurate way of obtaining the roots of a polynomial than
using Trace?
In a word, yes.
Do the following:
a) From the
graph screen press F5, G-Solv.
b) Press
F1(Root) and one root will be displayed after a few seconds.
c) If there
are other roots, press the left arrow and the next root will be displayed
after a few seconds. Additional
roots can be determined by repeating this procedure.
13) How can I
solve for the intersection of two graphs?
a)
From the graph screen press F5, G-Solv.
b) Press
F5(Insct) and one intersection will be displayed after a few seconds.
c) If there
are other intersections, press the left arrow and the next
intersection will be displayed after a few seconds.
Additional intersections can be determined by repeating this procedure.
===============================
III. MATRICES:
1) How do I enter a matrix in the CGX-9850BGB
Plus?
a) Press MENU, select the MAT icon and press
EXE.
b) Select the matrix (A, B, etc.) and enter the number of rows;
press EXE; enter the number of columns and press EXE.
The matrix with zeros entered will be displayed.
c) Enter the data, pressing EXE after each
entry.
d) Press EXIT to get back to the list of matrices.
2) How do I add two
matrices?
a) Press MENU, select the RUN icon and press EXE.
b)
Press OPTN, F2 (Mat), F1 (Mat), ALPHA, A, + where A is the
first of two matrices to add.
c)
Press F1 (Mat), ALPHA, B where B is the second matrix you want
to add.
d)
Press EXE and the sum of the two matrices will be displayed.
Of course subtraction is the same except that you use the subtract sign
instead of the add sign.
3) How do I
multiply a matrix by a scalar?
a) Press MENU, select the RUN icon and press EXE.
b) Press OPTN, F2 (Mat).
c) Press 4, F1 (Mat), ALPHA, A, EXE where A is the matrix to
be multiplied.
4) How do I
multiply two matrices?
a) Press MENU, select the RUN icon and press EXE.
b)
Press OPTN, F2 (Mat), F1 (Mat), ALPHA, A, x where A is the
first of two matrices to add.
c)
Press F1 (Mat), ALPHA, B where B is the second matrix you want
to add.
d)
Press EXE and the product of the two matrices will be displayed.
( 5) How do I
find the determinant of a matrix.
a) Press MENU, select the RUN icon and press EXE.
b) Press OPTN, F2 (Mat).
c) Press F3 (Det), F1 (Mat), ALPHA, A, EXE where A is the
matrix to be multiplied.
( 6) How do I do the rref and ref on a Casio CFX-9850GB
Plus calculator as the other people in my class do on their
TI-83.
There are several approaches you
can take. I would, of course, recommend my program casrefrref.:-) You can do
either ref and rref by selecting the
appropriate one from the menu. Suppose,
however, that
you're only spending a
lecture or so on matrices and don't want to take
the 20 minutes or so to enter my program. The next best thing is to
activate a program called ROWREDA that is already stored in the Casio
memory, but is
not active.. To learn how to activate that program,
go to my program casrefrref that can be referenced from the index
page of
my Website. The program ROWREDA will not give you the ref form but will
give you the rref form.
Finally, you can solve
the equations and make up your own rref matrix by hand. See item 6
below to do that.
(7) How do I find the inverse of a matrix on the Casio
CFX-9850/Plus?
a) First enter
the matrix in one of the positions, say matrix
A.
b) Press MENU. Then
select the RUN icon, and press EXE. That'll take you to the home
screen.
c) Press OPTN, F2; then
F1. Mat will appear on the home screen.
d) Enter the letter of the matrix
you want by using the ALPHA function and letter
keys.
e) Press SHIFT; then x-1
. x-1 is the key in the fourth row; fourth
column.
f) Press EXE. Your matrix
will be displayed if it has an inverse. If it has no inverse, you'll
get a Mat Error.
(8) How do I do matrix
row operations with the CFX-9850Plus?
It's pretty straight forward
on this calculator.
a) Highlight the MAT icon from Menu and
press [EXE].
b) Enter the dimensions of your matrix, press [EXE],
and enter the numbers for your matrix.
c) Press F1 (R-OP) and
select the type operation you want to perform. Numbers should be entered
in the order of
multiplier, row number being multiplied, row being added
to, as
appropriate.
(9) How do I activate the program ROWREDA to do
Gauss-Jordan?
(This CANNOT
be done on the CFX-9750 Plus.)
a) First select the icon PRGM and press
EXE.
b) Press F6; then F5(Load).
c) Scroll down to USA,
press EXE, then scroll down to ROWREDA and press EXE.
d) The
message "Load Completed" appears
soon.
(10) Is there some way I can get
a Gauss-Jordan solution to a matrix the way the TI-83 Plus does?
You can use the EQUA function, but it does have some limitations. You
will not be able to get any answer form a
system that has no solution. You will only get a math error indication.
For a system that has a solution, do the
following:
a) Press MENU, select the EQUA icon, and press EXE.
b) Select F1 (Simultaneous), and then select the number of unknowns by
pressing the appropriate F-key. For example,
press F2 for three unknowns.
c) Enter the coefficients and the constants into the matrix that is
displayed.
d) Press F1 (Solv) and the answers only will be displayed. If there
is no solution, you will get Mat Error.
e) If you need the answer in matrix form, you will need to make a matrix
by hand and enter the answers in a matrix
with zeros along the main diagonal.
=====================
IV. EQUATIONS:
(1) Is there a
way to solve quadratics on a CFX-9850Plus?
a) Highlight the EQUA
icon on the menu. Press [EXE].
b) Press F2 (POLY); then press F1
for degree 2.
c) Enter the coefficients and press F1
(SOLVE). The solution will appear as a 1x2 Matrix.
As an aside,
cubic equations can be solved
similarly.
(2) How do I solve a
system of equations on the TI-83Plus?
a) Highlight the EQUA
icon on the menu and press [EXE].
b) Select the maximum number of
unknowns by pressing the appropriate "F" key..
c) Enter the
coefficients of the equations and press F1
(SOLV).
===========================
V. FINANCIAL
CALCULATIONS: (More solutions will soon be added to
this section. 3/2/07)
(1) How do I do simple interest on a
Casio CFX-9850G Plus?
Generally, it is easier to just use the formula I=PRT for simple interest and
plug in the numbers on the calculator.
Nevertheless, I will explain how to
use the calculator with the following example: Find the interest and amount for a
loan of $1200 borrowed for 2 years at 7% interest.
a) Press MENU, select the TVM icon and press EXE.
b) Press F1, the SMPL key.
c) At the top of the screen you will notice either 360 or 365. It
doesn't matter which so long as the time for your problem
is in years, but you
will need that number
for the entry opposite "n." (Note that if the time is in days, you must
select the number of days for a year the your
problem specified if it is
different from the
number displayed at the top of the screen. That is done by pressing SHIFT,
SET UP; then pressing either F1 or F2 for
the correct number of days.
d) Assuming the number of days is set for 360, enter 2 x 360
opposite "n." The number 720 will be displayed.
e) Enter 7 opposite I% and -1500 opposite PV. ( If you leave
off the negative sign, your answer will be the same, but it
will be negative.
f) Press EXE to store the data and press F1 to get the answer of $150.
g) To get the amount, press F1; then F2 to get $1650.
(2) How do I do compound interest on a Casio CFX-9850G Plus?
Suppose you have $1000 and you need $1200 in three years. What interest
rate must you try to get to achieve your
goal?
a) Press MENU, select the TVM icon and press EXE.
b) Enter 3 opposite "n," skip I% and then enter -1000 opposite PV,
enter 0 opposite payment, and 1200 opposite FV,
1 opposite P/Y, and 2 opposite C/Y.
c) Press EXE to store the data and press F2 for I%. The answer, 6.27, will
be displayed for the interest.
3)
How do I do savings Accounts?
Suppose you need $2500.00 in 2 years and you can get 5% interest compounded
semiannually (twice a year). How
much must you deposit each month to obtain your goal of $2500?
a) Press MENU, select the TVM icon and press EXE. Press F2 for
compound interest.
b) Enter 2x12 opposite "n." Enter 5 opposite I%, 0 opposite PV,
-2500 opposite FV, 12 opposite P/Y, and 2 opposite
C/Y.
c) Press EXE to store the data.
d) Press F4 (PMT) to get the monthly payment of $99.31. (Note that
if you did not put the negative sign before the :V
amount, your payment answer will be negative.
4) How do I calculate the monthly payment on a mortgage?
Suppose you have a $200,000 loan for 20 years at an annual rate of 6.5%
compounded semiannually, what is the
monthly payment required?
a) Press MENU, select the TVM icon and press EXE.
b) Press F4 for amortization.
c) Press F2 (CMPD).
d) Enter 20 x 12 for "n," 6.5 for I%, 200000 for PV, skip PMT, enter zero
for FV, 12 for P/Y and 2 for C/y. Press EXE to
store this data.
e) Press F4 (Pmt) and the payment, -1314.25 will be displayed. The
negative sign indicates a cash outlfow.
===============================
VI. TRIGONOMETRY:
(1) How do I find
what the angle whose cos is 0.5?
First make sure that your calculator is set for radians or degrees, whichever
you want the answer in. (Usually you'll
want it in degrees.) To change the
mode, do
this:
a) Press SHIFT, SETUP; then cursor down to Angle and press F1, F2 or F3,
whichever one you want. Press EXIT to get
back to the home screen (RUN
screen). Now
to find COS-1 0.5, just press SHIFT, press the COS
button; then enter the
argument 0.5 and press EXE.
===============================
VII. CALCULUS:
(1) How do I find the
derivative on my Casio CFX-9850GB Plus?
First check the SET-UP to
make sure you have the derivative turned on. You can do that as
follows:
a) Press [SHIFT], [SET-UP]; then scroll down to
derivative. If On is shown, don't do anything. If On is not shown,
press F1. Secondly, the derivative works with Trace, so
you'll need to press [SHIFT], [TRACE] to get a readout of the
derivative as
you move along the function
curve.
(2)
How do I find the integral on my Casio CFX-9850GB Plus?
First check the SET-UP to
make sure you have the derivative turned on. You can do that as
follows:
a) Press [SHIFT], [SET-UP]; then scroll down to
"Integration," and select either Gauss or Simpson by pressing either F1 or
F2.
b) Assume we want the integral of ( 2x² +3x +4)dx from 1 to 5.
c) From the RUN screen press OPTN, F4 (CALC), F4 (∫dx), 2, [x, 0,
t], x², +, 3, [x, 0, T], +4, 1,5. The last two numbers are the
limits. If you want the tolerance, you can add that number. For
example, 1, [EXP], (-), ), would be added after the string
indicated above.
d) Press EXE and the value 134.6666....will be displayed.
=====================================
VIII. STATISTICS:
(1)
How do I graph a linear regression on the CFX-9850 Plus?
a)
Highlight the STAT icon and press [EXE].
b) Enter the x-data in
List 1 and the y-data in List 2.
c) Press F6 (SET), and scroll
down to Graph Type and press F1(Scat) if it's not already set. Set
up the other choices
such as List1 for XList and List2 for
YList.
d) Press [EXE]; then F1 (grph1). That'll do the
scatter plot.
e) Press F1 (X). That'll give you a, b, r ,
and r2.
f) Press F6 (Draw), and that'll draw the best
line.
VIII. MISCELLANEOUS:
(1)
When I enter (-32)^(1/5); then (-2)^3 I get a correct answer, -8, but when
I enter (-32)^(3/5) I get Ma ERROR.
Why?
It's probably because of the algorithm used in the last
case. The way most scientific calculators, the TI-82, and the
CFX-
9850 does xm/n is with the identity em/n*ln (x)
. As you can see, when you have -32 you have the natural log of a
negative number. That's a complex number and so is listed as an
error. For more on this topic, see item 13 on the
FAQs for
Scientific Calculators
============================
IX. ELECTRONIC
OPERATIONS:
(1) How do I
transfer a program from one Casio CFX-9850 Plus to
another?
a) Insure that the power is off on both calculators
and plug one end of the SB-62 unit-to-unit cable into each
calculator.
b) From the main menu page, select the LINK icon and
press EXE.
c) Press F2, RECEIVE, on the receive calculator.
Note that you must send data within six minutes or an error occurs.
You can press AC to cancel the transmit.
d) On the transmit
calculator, press F1, Transmit; then F1, Select.
e) Scroll
down to the program you want to transfer and press F6. You'll get a
Yes or No to confirm transmit. Press F1,
Yes. Transfer will
begin. If there's a problem, you will get a Transmit ERROR!
Press AC to clear the error. Press
MENU to get back to the menu
screen.
