How do you graph y<x-1 and y<=2x+1?

1 Answer
Aug 3, 2015

Plot each graph separately and then shade the area that satisfies both inequalities.

Explanation:

Your equations are y < x−1 and y≤2x+1

Step 1. Plot y = x-1.

Use a solid line because your condition is "less than", not “less than or equal to".

Graph 1

Step 2. Plot y = 2x+1

Use a dashed line because your condition is "less than or equal to".

Graph 2

Step 3. Shade the area that satisfies both conditions.

Shade the area that is below y = x-1 and below y = 2x+1.

Graph 3

Check Test a point in the coloured region.

Try (0,-2).

y < x-1
-2<0-1
-2<-1
∴ TRUE

y<= 2x+1
-2<=2(0)+1
-2=0+1
-2<=1
∴ TRUE

The point (0,-2) satisfies both conditions.