Sharp EL9900 manual + 2y ≤ 1 x 2 + y ≥, + 2y ≤ 1 y ≤ +y ≥ 4 y ≥ 4 x

EL-9900 Graphing Calculator

Graphing Solution Region of Inequalities

The solution region of an inequality consists of all points (a, b) such that when x = a, and y = b, all inequalities are true.

Example

Check to see if given points are in the solution region of a system of inequalities.

1. Graph the solution region of a system of inequalities:

x + 2y ≤ 1 x 2 + y ≥ 4

2. Which of the following points are within the solution region? (-1.6, 1.8), (-2, -5), (2.8, -1.4), (-8,4)

	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.

Step & Key Operation Display Notes

1-1

1-2

Rewrite the inequalities so that the left-hand side is y.

Enter y = 12-x for Y1 and y = 4 - x 2 for Y2.

Y= a/b 1 — X//T/n

2 ENTER 4 — X//T/n x2

x + 2y ≤ 1 ➞ y ≤	1-x
	2

x 2+y ≥ 4 ➞ y ≥ 4 - x 2

1-3Set the shade and view the solution					Y2 ≤ y ≤ Y1
region.
	2nd F	DRAW	G	1

2nd F VARS A

ENTER A 2

GRAPH2nd F VARS

GRAPH

ENTER 1

2-1Set the display area (window) to : -9 < x < 3, -6 < y < 5.

WINDOW

ENTER

(-) 9

(-) 6

ENTER 3

ENTER 5

ENTER

ENTER

9-4