Answer
-4x - 2
Explanation
To get the function needed, first calculate the slope of the graph.
slope = (change in y) / (change in x)
= (2 - -2)/(-1 - 0)
= 4/-1
= -4
Now use one of the point (-1, 2) in the graph and a general point (x,y) to find the function.
-4 = (y - 2)/(x - -1)
-4(x + 1) = y - 2
-4x - 4 = y - 2
y = -4x - 4 + 2
= -4x - 2
∴ f(x) = -4x - 2
