How do you graph the system of inequalities y<2x + 2, y> -x - 1?

1 Answer
Dec 8, 2017

See below.

Explanation:

First graph the equations y=2x+2 and y=-x-1. Use a dashed line as these are < and > and not <= and >= inequalities. This will give you the boundary lines.

Test an (x,y) coordinate in each section, to see which region is included or excluded.

Looking at graph, test coordinates in Areas A, B , C and D. These coordinates must satisfy both inequalities.

A (-1 ,3 )

-1<2(-1)+3color(white)(888) TRUE

-1> -(-1)-1color(white)(888) FALSE

A is an excluded region.

B( 1 , 1 )

1< 2(1)+2color(white)(888) TRUE

1>-(1)-1color(white)(888) TRUE

B is the included region.

Since we have found included region, we do not need to test any further.

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