Problem 2, part (a)
We locate -1 on the x axis. Then move up or down until reaching a marked point. In this case we move down to arrive at (-1,-2)
The x input x = -1 leads to the y output y = -2
Therefore, f(-1) = -2
-----------------------------------
Problem 2, part (b)
We follow the previous process in reverse. This time we start with the output, and we need to find which input(s) will get us there.
Draw a horizontal line through 3 on the y axis. This horizontal line crosses the marked points (0,3) and (2,3).
We can say that x = 0 leads to y = 3; also x = 2 leads to y = 3 as well.
In other words, f(0) = 3 and f(2) = 3
The two solutions to f(x) = 3 are x = 0 and x = 2