Sharp EL-9400 EL-9650/9600c/9450/9400 Graphing Calculator, x = -4, y =, y = 9.999999999 Note

EL-9650/9600c/9450/9400 Graphing Calculator

Step & Key Operation	Display	Notes
(When using EL-9650/9600c)	(When using EL-9650/9600c)
*Use either pen touch or cursor to operate.

2-1Enter the function

y=3.5x + 4for Y1. Enter y = 10 for Y2.

	Y=		CL		MATH			B	*
3		• 5						+
					X/ /T/n
1		0
2-2Set up shading.
	2nd F		DRAW	G		*	1 *

1*

4

ENTER *

Since the inequality you are solving is Y1 > Y2, the solu- tion is where the graph of Y2 is “on the bottom” and Y1 in

— — * * — *

2-3Set viewing window to “-10 < x < 10” and “-5 < y < 50” using Rapid Window feature and view the graph.

“on the top.”

WINDOW EZ 2 ENTER *

3 ENTER *

5 ENTER *

2-4Find the points of intersection. Solve the inequality.

		2		➞ x = -4, y = 10
2nd F	CALC		*
				➞ x = 1.714285714
2nd F	CALC	2	*

y = 9.999999999 ( Note)

The intersections are (-4, 10) and (1.7, 10.0). The solution is all values of x such that

x <- 4 or x >1.7.

( Note: The value of y in the intersection of the two graphs may not appear exactly as 10 as shown in the example, due to an error caused by approxi- mate calculation.)

The EL-9650/9600c/9450/9400 shows absolute values with , just as written on paper, by using the Equation editor. 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 Shade feature is useful to solve the inequality visually and the points of intersection can be obtained easily.

8-4