Casio ClassWiz fx-991EX User manual

QUICK START GUIDE
fx-991EX
www.casioeducation.com
The fx-991EX “ClassWiz” features a high-resolution
display, making it easier to view formulas and symbols.
This remarkable screen can display between 2-6 times
as many characters as other scientic calculators, yet
still runs on solar power.
Use the Wkey to turn the calculator on, and press
qC(OFF) to power the unit down.
The icon-based menu, accessible via the pkey,
allows easy navigation of features using the arrow keys
and the number keys or the Qshortcuts.
The okey can be used like Backspace in a word
processor to delete the character(s) left of the cursor.
The symbols printed on the keys use Natural Textbook
Display™ notation, similar to that found in textbooks.
This makes input of expressions fast and easy.
The nkey toggles your calculation results between
Standard (exact) and Decimal forms.

fx-991EX Quick Start Guide2
Icon Menu Name Description
CALCULATE Perform general computations using Natural Textbook Display™ notation, including
absolute value, logs of any base, summation, derivatives, and integrals.
COMPLEX Perform computations with complex numbers, including a + bi form, polar ( )
form, and conversions between the two.
BASE-N Perform binary, octal, and hexadecimal computations, and convert among those number
bases and base-10.
MATRIX Perform operations on matrices up to 4x4, including matrix arithmetic,
determinants, transpositions, and identity matrices.
VECTOR Perform operations on 2- and 3-dimensional vectors, including vector
arithmetic, dot products, angles, and unit vectors.
STATISTICS Calculate 13 different one-variable statistics, and apply linear, quadratic,
logarithmic, exponential, and geometric (power) regressions.
DISTRIBUTION Investigate Normal, Inverse Normal, Binomial, and Poisson probability and
cumulative distributions.
SPREADSHEET Create spreadsheets with up to 5 columns and 45 rows. Spreadsheet
supports Fill, Cut/Copy/Paste, recursive formulas, Mean, and Sum commands.
TABLE Create tables of values to compare up to 2 functions simultaneously.
EQUATION/
FUNCTION
Solve simultaneous (systems of) equations with up to 4 unknowns, and
polynomials of up to degree 4.
INEQUALITY Solve polynomial inequalities of up to degree 4, with the solution set expressed as
a compound inequality.
RATIO Solve proportions of the form A : B = X : D and A : B = C : X.
The following explains the meaning of each icon on the fx-991EX icon menu

fx-991EX Quick Start Guide 3
Below are some examples of the Natural Textbook Display™ input/output notation, as found by selecting the Calculate
icon from the Main Menu of the fx-991EX.
From the Main Menu, use the arrow keys to
highlight the Calculate icon, then press =
or press 1.
Fractions and mixed numbers can be entered using
aand qaA, respectively.
To enter the calculation to the left, press
a7$8$+qaA2$3$
11p.
To change the solution to a decimal format,
press n.
Press qnN to convert the result into
a mixed-number format.
When inputting radical expressions, the radical bar
automatically extends as additional characters are typed.
Press s24=.
The output will be displayed in simplest radical form, but can
be converted into a decimal approximation by pressing n.
CALCULATE

fx-991EX Quick Start Guide4
ClassWiz is capable of recognizing and combining like radicals.
Press s24$+s150=.
It can also calculate unlike radicals. Press
s24$-s98=.
Higher-order radicals can be beautifully expressed using
Natural Textbook Display™ input.
Press q^F5$64=.
Natural Textbook Display™ templates can be stacked
inside one another to allow input of complicated
expressions such as this quotient of rational exponentials.
Press a3^a1$2$$$3^-
2=.
In a trigonometry setting, arithmetic can be performed in
terms of π. Press a3qKC$4$+
2qKC=.
Other useful Natural Textbook Display™ templates that help
overcome typical calculator input frustrations include:
logarithms of any base,
ia1$2$$16=
(Note: the calculator does not generate a Syntax Error when the -key is used to create
a negative sign. Both -and zare acceptable for use.)
CALCULATE

fx-991EX Quick Start Guide 5
...summation (sigma) notation,
qxIxd+1$-3$7=
…derivatives of a function at a specic point (value),
qyY4xd-5x$0.2=
…and denite integrals.
ya1$x$$2$5=.
Settings for the “Calculate” mode can be accessed by pressing
qp(SET UP).
Press Rone or more times to reveal additional Setup options.
Solve x2 + Ax + Bx = 0 for x when A = 5 and B = 6.
Enter the equation by pressing, xd+Qz(A)
x+Qx(B) Qr(=)0.
SOLVE
The fx-991EX can elegantly solve an equation for any unknown using Newton’s method with the SOLVE command. To
use SOLVE, rst input the equation to be solved, then press qr(SOLVE).
CALCULATE

fx-991EX Quick Start Guide6
Input an initial guess for x followed by the values of A and B.
Pressqr(SOLVE) -5p5p6p.
Arrow back up to x= and SOLVE the equation by
pressing p.
To accomplish the same task and solve for A or B, enter a
value for x and a value for one of the other unknowns.
For example, to solve for A when x = 1 and B = 4, press
qr(SOLVE)1p2p4p.
Arrow back up to A= and SOLVE the equation by
pressing p.
The solution also displays L – R = 0. This means that
Newton’s method of approximation is directly on -5. If L – R
is not 0, simply recalculate to get a better approximation.
CALCULATE

fx-991EX Quick Start Guide 7
ENGINEERING CALCULATIONS
There are many menus in the fx-991EX that can handle engineering calculations. The fx-991EX has the power to
handle vectors, matrices, complex numbers and numerically calculates
summation and even denite integrals.
From the Main Menu, use the arrow keys to highlight the
Calculate icon and press por press 1.
There are many different types of unit conversions that can
be accomplished on this menu. To view the options, press
q8(CONV). Use the down arrow key (R) to see all the
possibilities.
Each one of the choices has a wide range of conversion options
for many different types of unit conversion.
Use the arrow keys to locate the Length conversion and press
1.
To convert 500 inches (in) into centimeters (cm), press Cto
return to the initial Calculate screen.
Press 500q8(CONV)1(Length)
1(in :cm)p.
CALCULATE

fx-991EX Quick Start Guide8
To find the difference between one US Gallon and one UK
Gallon, first, convert to a common unit, like a liter (L).
Press 1q8(CONV)3(Volume)
1(gal(US) :L)p.
One US gallon is approximately 3.785 L.
Now, convert the solution to gallons UK.
Press q8(CONV)3(Volume)4
(L :gal(UK))p.
It looks like a US gallon is smaller.
1 US gallon = 0.8326742321 UK gallons.
The same calculation can be accomplished using a
string of conversions.
Press 1q8(CONV)3(Volume)
1(gal(US) :L)q8(CONV)
3(Volume)4(L:gal(UK))p.
Start with a large number like 2.5 X 109.
Press 2.5K9p.
The gap between digits at place value separation can be viewed
by entering Set Up. Press qp(SET UP) and use the arrow
keys to navigate to the third menu.
ENGINEERING NOTATION
Converting large numbers into scientic and engineering notations
can be accomplished through a short series of keystrokes.
CALCULATE

fx-991EX Quick Start Guide 9
Press 4(Digit Separator)1(On) to turn on the Digit Separator
to show separation between place values.
Press p to recalculate the result and display clear place value
separation.
To convert this solution into engineering notation, use the b
key to change the solution into scientic notation. To move the
decimal to the right, press b.
To turn on the engineering symbols in setup, press
qw(SET UP).
Select 4(Engineer Symbol)1(On) to turn on the
Engineering Symbols.
Calculating with engineering symbols has never been easier.
To move the decimal to the left, press qbX.
CALCULATE

fx-991EX Quick Start Guide10
To calculate 500k (kilo) + 10M (Mega), press
500i3(Engineering Symbols)
6(k)+10i3(Engineering Symbols)
7(M)p.
The solution is displayed using the appropriate units.
Now, use theb key to convert between units.
CALCULATE

fx-991EX Quick Start Guide 11
Complex Number calculations can be executed in the Complex Mode.
From the Main Menu, use the arrow keys to highlight the
Complex icon, then press por press 2.
In Complex Mode, operations can be carried out using
the imaginary unit U. To add complex numbers, press
2+3bU+5-7bUp.
Complex numbers that are multiplied are displayed in
complex format. Press (3-2bU)
(5+6bU)p.
The argument of the complex number 1+2i, can be found by
taking the arctan (y/x) = 63.4349° or by using the Argument
command.
Press i1(Argument)1+2bU)p.
COMPLEX

fx-991EX Quick Start Guide12
COMPLEX FORM AND POLAR FORM
To convert a complex number into polar form, press
2+5bUiR1(:r∠q)p.
To convert any polar form of a complex number, use the r theta
command or type in the angle in polar form.
Press C2qbZ330iR
2(:a+bi)p.
Alternately, simply type in the angle in polar form by pressing
2qbZ330p.
These calculations can also be accomplished in radian mode.
To change to radian mode, press qp(SET UP)2(Angle
Unit)2(Radian).
COMPLEX

fx-991EX Quick Start Guide 13
Operations with matrices and matrix related calculations are all located in the Matrix Menu.
From the Main Menu, use the arrow keys to highlight the Matrix
icon and press p or press 4.
To enter matrices, rst, dene the matrix.
Press 1(MatA)2(Rows)2(Columns)
1p2pz3p4p.
To enter a second matrix, press i.
From the resulting popup window, press 1(Dene
Matrix)2(MatB).
Select the number of rows, 2(Rows).
Select the number of columns, 2(Columns).
MATRIX

fx-991EX Quick Start Guide14
Enter the matrix values by pressing
3pz6p8p2p.
To perform matrix calculations, like addition, subtraction, and
multiplication, follow these simple commands.
To recall the name of a matrix, press i.
To add A + B, press 3(MatA)+i4(MatB)p.
The solution matrix is displayed in the window and can be viewed
without scrolling.
To calculate the determinant of the matrix, press
iR2(Determinant) i3(MatA))p.
Matrices can be used to solve a system of equations.
Take the following equation with 3 unknowns:
Enter the coefcient matrix as Matrix A and the solution matrix as Matrix B.
MATRIX

fx-991EX Quick Start Guide 15
Redene the matricies by pressing i1
(Dene Matrix).
Press 1(MatA) to dene Matrix A and enter the
3 x 3 coefcient matrix.
Select the number of rows, 3(Rows).
Select the number of columns, 3(Columns).
Enter the values of the coefcients, pressing pafter
each one to move to the next value.
Now, enter the 3 x 1 solution matrix as Matrix B.
Press i1(Dene Matrix).
Dene Matrix B 2(MatB) as a 3 x 1, so select 3(Rows)
and 1(Columns) from the next two windows.
MATRIX

fx-991EX Quick Start Guide16
Enter the values of the coefcients, pressing pafter each
one to move to the next value.
Press Cto return to the Matrix Calculation screen.
The solution can be found by calculating A-1 x B.
Press i3(MatA)uOi4(MatB)p.
The solution represents the following:
This same system can also be solved using the Equation icon.
MATRIX

fx-991EX Quick Start Guide 17
The fx-991EX is capable of handling vector calculations with vectors in 2 or 3 dimensions.
From the Main Menu, use the arrow keys to highlight the
Vector icon and press por press 5.
Let vectors uand vbe dened in the 3-dimensional plane by the
following: u= 2i + 3j – 2k and v= 3i - 4j + 5k
Dene uas Vector Awith dimension 3.
Press 1(VctA)3(Dimension).
Enter the components of the vector and press pafter each one
to move to the next value.
Dene vas Vector Bwith dimension 3.
Press i1(Dene Vector).
Press 2(VctB)3(Dimension).
VECTOR

fx-991EX Quick Start Guide18
Enter the components of the vector and press pafter each
one to move to the next value.
To execute basic vector operations, press Cto enter
Vector calculation.
Recall the names of the vectors and execute the desired
operation by pressing i.
Vector addition, subtractions, and multiplication are all available.
For subtraction, press 3(VctA)-i4(VctB)p.
For multiplication, press
i3(VctA)Oi4(VctB)p.
The sums of the product of the components of a vector
are known as the vector’s dot product. So,
.
Press i3(VctA)iR2(Dot Product)i4(VctB)
p.
VECTOR

fx-991EX Quick Start Guide 19
Even some very complex vector operations like the angle between vectors, which is dened as in
which are easily accomplished on the fx-991EX.
To calculate vector cross product (not vector multiplication),
press iR3(Angle)i3(VctA)q)(,)i
4(VctB))p.
VECTOR

fx-991EX Quick Start Guide20
The fx-991EX can calculate several one-variable statistics, and also analyze relationships between two data sets
using various regression models.
From the Main Menu, use the arrow keys to highlight the
Statistics icon, then press por press 6.
On the resulting menu, select 1for “1-Variable” statistics.
A data entry screen appears.
This example uses the following list of some students’ heights,
given in inches: 70.5, 74, 67, 71, 71, 72, 73.5, 72, 69, 71.
Enter data by typing in each value one at a time, with each
followed by the p key.
70.5p,74p, etc.
To calculate the 1-Variable statistics for this data set,
press i3(1-Variable Calc).
STATISTICS