You have to determine all x, for which f(x)>-2.
First, draw a horizontal line. that passes through the point (0,-2). This line intresects the graph of the given function in points (2,-2) and (8,-2). You can see that:
- for 2<x<8, the graph of the function is above this horizontal line, then f(x)>-2;
- for x<2 and x>8, the graph of the function is below this horizontal line, then f(x)<-2;
- for x=2 and x=8, the graph of the function intersects this horizontal line, then f(x)=-2.
Answer: correct choice is D.
