FAQs FOR CASIO GRAPHING CALCULATORS
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Index:
(1) How do I graph a piecewise function on a Casio CFX-9850GP Plus?
(2) 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?
(3) What's the best graphing calculator to buy, and where's the best place
to buy one?
(4) How do I find the inverse of a matrix on the Casio
CFX-9850/Plus?
(5) How do I activate the program ROWREDA to do Gauss-Jordan?
(6) When I enter an equation with large coefficients, I often can't find
the graph on my CFX-9850Plus. How do I find it?
(7) How do I graph a circle on the CFX-9850Plus?
(8) How do I draw a circle on a graph?
(9) How do I find what the angle whose cos is
0.5?
(10) How do I transfer a program from one Casio CFX-9850 Plus to another?
(11) How do I graph an inequality on the CFX-9850+ and do the shading?
(12) How do I find the derivative on my Casio CFX-9850GB Plus?
(13) Is there a way
to solve quadratics on a CFX-9850Plus?
(14) How do I solve a system of equations on the CFX-9850Plus?
(15) How do I do matrix row operations with the CFX-9850Plus?
(16) How do I set up the domain for a function on a CFX-9850Plus?
(17) How do I graph a linear regression on the CFX-9850+?
(18) 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?
(19) Isn't there a way to edit entries on the CFX-9850 the way my friends
use ENTRY on the TI-83 Plus?
(20) My CFX-9850 won't scroll past the certain number is a table.
How can I fix that?
Answers:
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DISCLAIMER:
The FAQs
on this web site, and especially FAQ #3, reflect the writer's subjective
opinion and observations. The FAQs should be considered only as another source
of information. The writer is not endorsing any particular brand or model of
the calculators mentioned or any particular store or shop. The writer does not
warrant the accuracy of any FAQ. Any calculator mentioned may not be a
representative sample of what is on the market, and the manufacturers may change
their products or specifications without my knowing about it.
(1) 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
The 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.
===========
(2) 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 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. 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. To do that for rref (won't work for ref) you can
solve the equations using EQUA from the icon menu. Then set up a matrix on a sheet of paper that has
the same dimensions as the one you solved. Fill in the diagonal with 1s
and the last column with the answers you got with the EQUA function. Fill
in all other positions with 0s.
You can do ref using the row operations capability of the
calculator. That's beyond the scope of this short description, and many
students in the college algebra and elementary calc level of math find it a
tedious process. If you're an engineer or science major, it should be no
problem.
==============
(3) What's the best graphing calculator to buy, and where's the best place
to buy one.
Caveat:
The following is an attempt to give some help to those who are unfamiliar
with the capabilities of graphing calculators and how their capabilities relate
to courses of study. It is not intended as definitive advice on what
a particular student should buy. I
would appreciate knowing of any disagreements you have with me. Send me an
e-mail by clicking Webmaster in the navigation bar.
Bottom Line: Talk with the teachers of the classes
you're going to be taking. Buy the calculator that they're going to be
using in their instructions if you can afford it and don't already have another
type.
Guidelines: If the
teachers don't use calculators, or if you're enrolled in a distance course or
some other situation prevents your consulting the teachers, here are some
guidelines. Please realize that it's ultimately up to you to make the
decision based on what information you collect. This is only one source of
information. So, the following is a set of guidelines based on the level
of math you might be taking.
General Discussion: If you're a real math and calculator geek and money is not a
problem, you'd probably be happier with the TI-89. If you are mainly interested
in a tool to do your math in the most efficient way, then a TI-83 Silver
addition would be entirely sufficient for courses that don't include functions
of more than one variable. That unusually comes in second semester calculus. The
TI-83 Plus is simple to use and fairly versatile.
I would point out that it is possible to graph functions of more
than one variable on a TI-83, but you have to hold all but one variable
constant. For example, if you want to graph e^-(x² +y²), you could replace y²
with A, and supply constant values of A from the home screen to get a family of
curves. I understand that TI is developing a set of applications that will give
the TI-83 Plus some of the capability of the TI-89. If you buy the TI-83 Plus, you get the GraphLink
or Connect software that allows you to download applications
from the Internet to your calculator.
For taking derivatives and integrals of functions of more than one
variable, the TI-86 would be suitable and, in my opinion, it's somewhat simpler
to use than the TI-89. The last time I checked it was also cheaper.
If you want the ultimate in graphing calculators, then go with the TI-89. As I
previously said, if you're not really into calculators, it's going to take quite
a lot of studying of the manual to learn to use it.
And Now: The following is an attempt to give some
idea of what calculator might be needed for a particular set of courses of
study.
High School: I don't have
contact with high school students, so I don't have a good feel for their needs.
Generally, I would think that if you're not planning to take Pre-calculus
or AP Calculus, a good scientific calculator would be entirely satisfactory.
(FAQ 1 on the Scientific Calculator FAQs is about buying a scientific
calculator.) But be sure to check with some of the teachers to see if they
might use graphing calculators for doing graphs is Algebra II.
Incidentally, scientific calculators are sometimes more efficient and easier to
use than graphing calculators.
If you plan to take Pre-calculus or AP Calculus,
and especially if you're planning to major in engineering, science, or math in
college; then you probably should buy a graphing calculator if the cost is not a
problem with you. A TI-83Plus or a Casio Cfx-9850GB would be sufficient,
but I would be remiss if I didn't say that the TI-83Plus is more often the
choice among college students. Be cautious about buying a TI-86 or TI-89.
Although these are excellent for those who have a more than average interest in
math, many students never really learn to use these calculators with anything
like their potential.
Developmental Math: For
Basic Math and Beginning Algebra, Elementary Algebra, or whatever your school
calls it, you can get by with a good scientific calculator. Don't buy one
of those six-or eight-function calculators. They're not worth carrying
around. Don't pay more than $14.95 if you're on a tight budget. See
my Scientific Calculator FAQs, FAQ #1, for more information on buying a scientific
calculator.
For Intermediate Algebra, you may need a graphing
calculator depending on whether your school uses one. In any case, it
would be nice to have one to check your answers. Make your decision based on your
major as listed in the categories below.
Elementary School Teacher, Nursing, Liberal Arts,
Communications: I'm assuming you're going to take
College Algebra and either Elementary Calculus or something like Foundations of
Mathematics. Unless you're some kind of calculator guru, don't buy one of
the heavy hitters like a TI-89. Chances are you'll never understand how to
use all its power. Instead, buy a TI-83 Plus or a Casio CFX-9850GB Plus.
You can get by with a TI-82 if you'll enter my program for doing rref and ref on
augmented matrices and, for finite math, the program for doing the simplex
method. Otherwise you're going to be left out when you get to
doing augmented matrices or simplex. The Casio has a program that you'll need to
activate for doing rref, or you could use my program for rrefref for the Casio.
That'll give you both ref and rref. If your teacher is one of those who
gives you a lot of augmented matrix work to do by hand, you might find my matrix
row operations program helpful for both the TI and the Casio.
Suppose you absolutely can't afford any graphing calculator.
Hang in there and get you a good scientific for no more than $14.95. Go to
the Tutoring Lab, Learning Center, Academic Assistance Center or whatever your
school (community colleges) calls it and use their calculator to do your
homework. They may even have one you can check out and take to do tests.
You might also ask your professor about one of the cheaper Casios:
FX-7400G Plus or FX-9750 Plus. I have an older FX-9750, and I worked some
with an older FX-7400, but I am not familiar enough with the newer versions of
these calculator to give advice on them. Read my notesbelow on the
Durabrand that has recently appeared at Wal-Mart for $1995.
Economics and Heavy Business Courses:
I'm assuming you'll take Calculus I and Finite Mathematics with some other
financial courses. The finite math may be heavy in linear
programming and the Simplex method. Be sure to find out if your teacher
uses one of those special financial calculators in your class. Otherwise,
you can use a TI-83 Plus or a Casio CFX-9850GB Plus. The Casio has a
program called LINPROG that needs to be activated for doing simplex. You can use my program
called LINPRG2 for the TI-83 Plus to do the Simplex method. Both of these
calculators have functions for doing amortization, different types of interest,
and other financial functions.
Chemistry: You guys probably know what
you need. If you're going to take Calc I and II and no differential
equations you probably could get by with a TI-83 Plus or a Casio CFX-9850GB Plus.
If you're going to take higher math, buy one of the heavy hitters like a TI-86
or TI-89.
Electrical Engineers & Physicists: You
guys know what you need. If you don't, talk with your professors. My
inclination: Don't buy one of the simpler graphing calculators. Buy
one of the heavy hitters. You need the best tools you can get.
Where to buy: I'm not going to tell you
where to buy; I'm going to tell you some places they're available.
Wal-Mart, Best Buys, Home Depot, Office Depot, Target (I believe Target still
has them.), and others that may be specific to your area. If you want to
save money, watch the advertising inserts to your local newspaper about the time
the fall semester starts. Many stores have significant savings at that
time. Call around and see who has the best price.
Now, here's something that may seem a little weird to you,
but it works for many of the students who come to me and are pressed for money.
I send them to pawn shops. Many pawn shops in this area have used TI-83
Plus calculators for $35 to $45 dollars. I tell the students to make
the pawn shop dealer agree to take the calculator back for a couple days or so,
until they come in and have me check it out. You might also try to bargain
a little by telling the dealer that the TI-83 Plus is now two versions out of
date. Now, let me give you a little
hint on getting a calculator from the pawn shop: Turn the calculator on;
press 2nd, MEM, ENTER. In the middle of the screen, right below the
TI-83Plus will be an entry such as 1.19. This is the version of the
operating system and may tell you indirectly how old the calculator is.
(I say may because someone, like me, may have upgraded the operating system.) The
higher the number, the newer, with 1.19 being the highest as of 6/1/06.
If the pawn shop has several calculators, try them all and get the one with the
latest version unless you have to pay considerably more. Try to get one with
1.14 or higher. If you must settle for a lower number, tell the dealer
that it's old and he should give you a price break on it. If you have a
friend with Connect or GraphLink installed, you can upgrade the operating
system.
Now, how about the Durabrand calculator that has recently
appeared at Wal-Mart for $19.95? Here's what little preliminary
information I have on it. (Please read the DISCLAIMER at the start of
these FAQs)
PROS:
* Has a 50-key keyboard that appears to
be fairly well arranged except, possibly for the SHIFT key.
* Has fraction and Ans keys.
* Has sufficient memories for most any purpose -
26.
* Has about any of the standard algebraic and
trig functions that you would want - including one- and two-variable
statistics.
* Algebraic entry of formulas.
* Easily obtained battery - CR2032. This is the
same as the battery used for the memory in the TI-83 Plus.
* Has some limited programming ability.
CONS:
* The display for the graph is very small, 35 x
23 pixels. The full-screen display on the TI-83 Plus is 62 x 94 and
the split-
screen G-T display is 50 x 46.
* As far as I can see, there is no equivalent of the ENTRY
function on the TI-83 Plus. This is very useful when you need to use
a long expression and only edit a number or
maybe two.
* Programming is limited to 400 steps divided among ten
pre-designated programs. Gamers, forget about it.
SUMMARY OF DURABRAND CALC:
Don't let the small number of
cons lead you to believe this is equivalent to the TI-83 Plus or the Casion
CFX-9850 series. This is more on the order of the old Casio 7000G Graphic
calculator. This is merely my opinion, but I'd try to come up with 15 to
20 dollars more money and look hard for a used TI-83 Plus or equivalent.
===============
(4) 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.
===================
(5) How do I activate the program ROWREDA to do
Gauss-Jordan?
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.
=====================
(6) 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)
--------------------------
(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 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 = or EXE.
---------------------------------------
(10) 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.
__________________
(11) How do I graph an 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.
_____________________
(12) 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 [2nd], [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 [2nd],
[Trace] to get a readout of the derivative as you move along the function curve.
----------------------------------
(13) 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.
_______________________
(14) 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).
________________________
(15) 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.
______________________________
(16) 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
a) 3x-1, [-5,0]. Then press [EXE], F6. That's all there is to it.
__________________________
(17) How do I graph a linear regression on the CFX-9850+?
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 r^{2}.
f) Press F6 (Draw), and that'll draw the best line.
--------------------------------------------
(18) 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 x^^{m/n} is
with the identity e^{m/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
(19) 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.
(20) 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.
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 (INTG); then press
SHIFT, F1(TRACE), and you can use the cursor to scroll through different
x-values.
Released: 3/17/04
Last Revised: 3/31/07