Look at the graph. To find the rate of change of the function, Kevin did the following:

StartFraction 0 minus (-1) Over 2 - 2.5 EndFraction = StartFraction 1 Over -0.5 EndFraction = -2.

What was Kevin's mistake?
He incorrectly chose (4,0) as a point on the graph.
He incorrectly chose (0,2) as a point on the graph.
He mixed up the numerator and the denominator of the fraction.
He subtracted -2 from 0 when he should have added -2 to 0.