EL-9600/9400 Graphing Calculator
Step & Key Operation
(When using EL-9600) *Use either pen touch or cursor to operate.
Display
(When using EL-9600)
Notes
2-1
Enter y = 3(4 - 2x) for Y1 and y = 5 - x for Y2.
Y=
ENTER
* *
5
(7 times) DEL (4 times)
�
X/ /T/n
2-2
View the graph.
GRAPH
2-3
Access the Set Shade screen.
2nd F DRAW
G
*
1
*
2-4
Set up the shading.
� �
*
*
�
*
Since the inequality being solved is Y1 � Y2, the solution is where the graph of Y1 is �on the top� and Y2 is �on the bottom.�
2-5
View the shaded region.
GRAPH
2-6
Find where the graphs intersect and solve the inequality.
2nd F CALC
2
*
The point of intersection is (1.4, 3.6). Since the shaded region is to the left of x = 1.4, the solution to the inequality 3(4 - 2x) � 5 - x is all values of x such that x � 1.4.
Graphical solution methods not only offer instructive visualization of the solution process, but they can be applied to inequalities that are often difficult to solve algebraically. The EL-9600/9400 allows the solution region to be indicated visually using the Shade feature. Also, the points of intersection can be obtained easily.
