Solving A System Of Equations By Graphing Or Tool Feature - Sharp EL-9900 Handbook Vol. 1 Operation Manual

Solving a System of Equations by Graphing or Tool Feature

A system of equations is made up of two or more equations. The calculator provides the
Calculate feature and Tool feature to solve a system of equations. The Calculate feature
finds the solution by calculating the intersections of the graphs of equations and is useful
for solving a system when there are two variables, while the Tool feature can solve a linear
system with up to six variables and six equations.
Example
Solve a system of equations using the Calculate or Tool feature. First, use the Calcu-
late feature. Enter the equations, draw the graph, and find the intersections. Then,
use the Tool feature to solve a system of equations.
1.
Solve the system using the Calculate feature.
y = x 2 - 1
{
y = 2x
2.
Solve the system using the Tool feature.
5x + y = 1
{
-3x + y = -5
Before
There may be differences in the results of calculations and graph plotting depending on the setting.
Starting
Return all settings to the default value and delete all data.
Set viewing window to "-5 < X < 5", "-10 < Y < 10".
(-)
WINDOW
As the Tool feature is only available on the Advanced keyboard, example 2 does not apply to the
Basic keyboard.
Step & Key Operation
1
1
- Enter the system of equations
2
y = x - 1 for Y1 and y = 2x for Y2.
x
n
2
Y= X/ /T/
n
2 X/ /T/
1
2
- View the graphs.
GRAPH
1
3
Find the left-hand intersection using
-
the Calculate feature.
2
2nd F CALC
1
4
Find the right-hand intersection by
-
accessing the Calculate feature again.
2
2nd F CALC
5
ENTER 5 ENTER
— 1
ENTER
EL-9900 Graphing Calculator
Display
Note that the x and y coordi-
nates are shown at the bot-
tom of the screen. The answer
is : x = - 0.41 y = - 0.83
The answer is : x = 2.41
y = 4.83
Notes
7-1