Answer: 1
Step-by-step explanation
Draw a vertical line through -1 on the x axis.
This vertical line crosses the curve at some point, which I'll refer to as point P.
From point P, move horizontally until reaching the y axis. You should arrive at y = 1.
Therefore, f(-1) = 1
The input x = -1 leads to the output y = 1
The location of point P is (x,y) = (-1,1)