Critical numbers are -4 and -2

The critical numbers are not part of the solution.

Open circle those on a number line:

----------o-----o----------------
-7 -6 -5 -4 -3 -2 -1  0  1  2  3

Choose a test value left of -4, say -5

Substitute x=-5 in






False so we do not shade the interval left of -4

----------o-----o----------------
-7 -6 -5 -4 -3 -2 -1  0  1  2  3

Choose a test value between of -4 and =-2, say -3

Substitute x=-3 in






True, so we do shade the interval between -4 and -2

----------o=====o----------------
-7 -6 -5 -4 -3 -2 -1  0  1  2  3

Choose a test value right of -4, say 0

Substitute x=0 in






False so we do not shade the interval right of -2

So the set-builder notation is {x|-4 < x < -2}

So the interval notation of the graph is (-4,-2).

Edwin