Casio fx-7400G PLUS User manual

Graphing
A collection of versatile graphing tools plus a large 79 ×47-dot
display makes it easy to draw a variety of function graphs quickly
and easily. This calculator is capable of drawing the following types
of graphs.
•Rectangular coordinate (Y =) graphs
•Parametric graphs
•Inequality graphs
•Aselection of graph commands also makes it possible to incorpo-
rate graphing into programs.
1. Before Trying to Draw a Graph
2. View Window (V-Window) Settings
3. Graph Function Operations
4. Drawing Graphs Manually
5. Other Graphing Functions
Chapter
4

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Chapter 4 Graphing
1. Before Trying to Draw a Graph
kk
kk
kEntering the Graph Mode
On the Main Menu, select the GRAPH icon and enter the GRAPH Mode. When you
do, the Graph Function (G-Func) menu appears on the display. You can use this
menu to store, edit, and recall functions and to draw their graphs.
1(SEL) ........ Draw/non-draw status
2(DEL) ........ Graph delete
4(DRAW) .... Draws graph
2. View Window (V-Window) Settings
Use the View Window to specify the range of the x-and y-axes, and to set the spac-
ing between the increments on each axis. You should always set the View Window
parameters you want to use before drawing a graph. Press !3to display the
View Window.
1. Press !3 to display the View Window.
!3(V-Window)
1(INIT) ........ View Window initial settings
2(TRIG) ...... View Window initial settings using specified angle unit
3(Sto) ......... Store View Window settings to View Window memory.
4(Rcl) .......... Recall View Window settings from View Window memory.
Xmin................ Minimum x-axis value
Xmax............... Maximum x-axis value
Xscl ................. Spacing of x-axis increments
Memory area
Use
f and c to change selection.
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Graphing Chapter 4
2. Input a value for a parameter and press w. The calculator automatically selects
the next parameter for input.
•You can also select a parameter using the cand fkeys.
Ymin................ Minimum y-axis value
Ymax............... Maximum y-axis value
Yscl ................. Spacing of y-axis increments
The following illustration shows the meaning of each of these parameters.
3. Input a value for a parameter and press w. The calculator automatically selects
the next parameter for input.
•There are actually nine View Window parameters. The remaining three param-
eters appear on the display when you move the highlighting down past the Y
scale parameter by inputting values and pressing c.
Tmin ................ T minimum values
Tmax ............... T maximum values
Tptch ............... T pitch
The following illustration shows the meaning of each of these parameters.
X max
Y scl
Y min
Y max
(x, y)
X min
X scl
min
max
ptch
( X, Y )

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Chapter 4 Graphing
4. To exit the View Window, press Q.
•Pressing wwithout inputting any value also exits the View Window.
•The following is the input range for View Window parameters.
–9.99E+97 to 9.999E+97
•You can input parameter values up to 7 digits long. Values greater than 106or
less than 10-1
, are automatically converted to a 4-digit mantissa (including nega-
tive sign) plus a 2-digit exponent.
•The only keys that enabled while the View Window is on the display are: ato
j, ., E, -, f, c, d, e, +, -, *, /, (, ), !7,
Q. You can use -or -to input negative values.
•The existing value remains unchanged if you input a value outside the allow-
able range or in the case of illegal input (negative sign only without a value).
•Inputting a View Window range so the min value is greater than the max value,
causes the axis to be inverted.
•You can input expressions (such as 2π) as View Window parameters.
•When the View Window setting does not allow display of the axes, the scale for
the y-axis is indicated on either the left or right edge of the display, while that for
the x-axis is indicated on either the top or bottom edge.
•When View Window values are changed, the graph display is cleared and the
newly set axes only are displayed.
•View Window setting may cause irregular scale spacing.
•Setting maximum and minimum values that create too wide of a View Window
range can result in a graph made up of disconnected lines (because portions of
the graph run off the screen), or in graphs that are inaccurate.
•The point of deflection sometimes exceeds the capabilities of the display with
graphs that change drastically as they approach the point of deflection.
•Setting maximum and minimum values that create to narrow of a View Window
range can result in an error (Ma ERROR).
kk
kk
kInitializing and Standardizing the View Window
uu
uu
uTo initialize the View Window
a. Press !3 (V-Window) 1(INIT) to initialize the View Window to the following
settings.
Xmin = –3.9 Ymin = –2.3
Xmax = 3.9 Ymax = 2.3
Xscl = 1 Yscl = 1

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Graphing Chapter 4
b. Press !3(V-Window) 2(TRIG) to initialize the View Window to the follow-
ing settings.
Deg Mode
Xmin = –360 Ymin = –1.6
Xmax = 360 Ymax = 1.6
Xscl = 90 Yscl = 0.5
Rad Mode
Xmin = –6.28318
Xmax = 6.28318
Xscl = 1.57079
Gra Mode
Xmin = –400
Xmax = 400
Xscl = 100
•The settings for Ymin, Ymax, Ypitch, Tmin, Tmax, and Tpitch remain unchanged
when you press 2(TRIG).
kk
kk
kView Window Memory
You can store a set of View Window settings in View Window memory for recall when
you need them.
uu
uu
uTo save View Window settings
While the View Window setting screen is on the display, press 3(Sto) to save the
current settings.
•Whenever you save View Window settings, any settings previously stored in
memory are replaced.
uu
uu
uTo recall View Window settings
While the View Window setting screen is on the display, press 4(Rcl) to recall the
View Window settings stored in memory.
•Whenever you recall View Window settings, the settings on the View Window are
replaced by the recalled settings.
•You can change View Window settings in a program using the following syntax.
View Window [Xmin value], [Xmax value], [Xscl value],
[Ymin value], [Ymax value], [Yscl value],
[Tmin value], [Tmax value], [Tptch value]

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Chapter 4 Graphing
3. Graph Function Operations
You can store up to 10 functions in memory. Functions in memory can be edited,
recalled, and graphed. The types of functions that can be stored in memory are:
rectangular coordinate functions, parametric functions, and inequalities.
kk
kk
kSpecifying the Graph Type
Before you can store a graph function in memory, you must first specify its graph
type.
1. While the Graph Function Menu is on the display, press [to display a Graph
Type Menu.
[
1(Y =) ......... Rectangular coordinate graph
2(Parm) ...... Parametric graph
[
1(Y >) ......... Y > f (x) inequality
2(Y <) ......... Y < f
(x) inequality
3(Y ≥)......... Y >f
(x) inequality
4(Y ≤)......... Y <f
(x) inequality
Press [to return to the previous menu
2. Press the function key that corresponds to the graph type you want to specify.
kk
kk
kStoring Graph Functions
uu
uu
uTo store a rectangular coordinate function (Y =)
Example To store the following expression in memory area Y1:
y= 2 x2– 5
[1(Y =)
(Specifies rectangular coordinate
expression.)
cTx-f
(Inputs expression.)
w
(Stores expression.)
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53
Graphing Chapter 4
•You will not be able to store the expression in an area that already contains a
parametric function. Select another area to store your expression or delete the
existing parametric function first. This also applies when storing inequalities.
uu
uu
uTo store a parametric function
Example To store the following functions in memory areas Xt2 and Yt2:
x= 3 sin T
y= 3 cos T
[2(Parm)
(Specifies parametric expression.)
dsTw
(Inputs and stores xexpression.)
dcTw
(Inputs and stores yexpression.)
•You will not be able to store the expression in an area that already contains a
rectangular coordinate expression or inequality. Select another area to store your
expression or delete the existing expression first.
uu
uu
uTo store an inequality
Example To store the following inequality in memory area Y3:
y> x2– 2x– 6
[[1(Y>)
(Specifies an inequality.)
Tx-cT-g
(Inputs expression.)
w
(Stores expression.)

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Chapter 4 Graphing
kk
kk
kEditing Functions in Memory
uu
uu
uTo edit a function in memory
Example To change the expression in memory area Y1 from y= 2x2– 5
to y= 2x2– 3
e
(Displays cursor.)
eeeed
(Changes contents.)
w
(Stores new graph function.)
uu
uu
uTo delete a function
1. While the Graph Function Menu is on the display, press for cto display the
cursor and move the highlighting to the area that contains the function you want
to delete.
2. Press 2(DEL).
3. Press 1(YES) to delete the function or 4(NO) to abort the procedure without
deleting anything.
kk
kk
kDrawing a Graph
Before actually drawing a graph, you should first make the draw/non-draw status.
uu
uu
uTo specify the draw/non-draw status of a graph
You can specify which functions out of those stored in memory should be used for a
draw operation.
•Graphs for which there is no draw/non-draw status specification are not drawn.
Example To select the following functions for drawing:
Y1 : y= 2x2– 5
Xt2: x= 3 sin T
Yt2: y= 3 cos T
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55
Graphing Chapter 4
Use the following View Window parameters.
Xmin = –5 Ymin = –5
Xmax = 5 Ymax = 5
Xscl = 1 Yscl = 1
ccc
(Select a memory area that contains a
function for which you want to specify
non-draw.)
1(SEL)
(Specify non-draw.)
4(DRAW) or w
(Draws the graphs.)
•Pressing uor Areturns to the Graph Function Menu.
•Aparametric graph will appear coarse if the settings you make in the View
Window cause the pitch value to be too large, relative to the differential be-
tween the min and max settings. If the settings you make cause the pitch value
to be too small relative to the differential between the min and max settings, on
the other hand, the graph will take a very long time to draw.
4. Drawing Graphs Manually
After you select the RUN icon in the Main Menu and enter the RUN Mode, you can
draw graphs manually. First press !4(SKTCH) 2(GRPH) to recall the Graph
Command Menu, and then input the graph function.
!4(SKTCH)2(GRPH)
1(Y =) ......... Rectangular coordinate graph
2(Parm) ....... Parametric graph
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Unhighlights

56
Chapter 4 Graphing
[
1(Y >) ......... Y > f (x) inequality
2(Y <) ......... Y < f
(x) inequality
3(Y ≥)......... Y >f
(x) inequality
4(Y ≤)......... Y <f
(x) inequality
Press [to return to the previous menu.
uu
uu
uTo graph using rectangular coordinates (Y =)
You can graph functions that can be expressed in the format y= f(x).
Example To graph y= 2x2+ 3x– 4
Use the following View Window parameters.
Xmin = –5 Ymin = –10
Xmax = 5 Ymax = 10
Xscl = 2 Yscl = 5
1. In the set-up screen, specify the appropriate graph type for F-Type.
!Z1(Y =)Q
2. Input the rectangular coordinate (Y =) expression.
A!4(SKTCH)1(Cls)w
2(GRPH)1(Y =)
cTx+dT-e
3. Press wto draw the graph.
w
•You can draw graphs of the following built-in scientific functions.
• sin x• cos x• tan x• sin–1 x• cos–1 x
• tan–1 x• • x2• log x• lnx
• 10x• ex• x–1 • 3
View Window settings are made automatically for built-in graphs.
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