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Inequalities – Sharp EL-9900 User Manual

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Basic Keyboard/ALGEBRA USING THE SHARP EL-9900

Copyright © 2002, Sharp Electronics Corporation. Permission is granted to photocopy for educational use only.

1.

To solve the inequality 3(4 – 2x)

≥ 5 – x, press Y= CL , enter 3(4 – 2X) for

Y1 and 5 – X for Y2.

2.

Set the viewing window by pressing ZOOM

A (ZOOM) 5 (Default).

3.

Next, shade the set of points that make the inequality true by pressing 2ndF

DRAW G (SHADE) 1 (Set) to access the “Set Shade” screen. Since the

inequality you are solving is Y1

≥ Y2 the solution is where the graph of Y1 is

“on the top” and Y2 is "on the bottom." Do this by pressing 2ndF VARS A

ENTER 2 2ndF VARS ENTER 1 . Press GRAPH to view the

shaded region.

4.

Press 2ndF CALC 2 (Intsct) to find where the graphs intersect.

5.

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.

6.

Turn off the shading by pressing 2ndF DRAW G (SHADE) 2 (INITIAL).

INEQUALITIES