find the rate of change of f(x)=x^2+4

a. from -2 to 0
b. from 1 to 3
c. from -2 to 1

please show work

I will do the last one, you do the first two in the same way ...

f(-2) = (-2)^2 + 4 = 8
f(1) = 1 + 4 = 5

rate of change = ( f(x2 - f(x1))/(y2 - y1)
= (5-8)/(1-(-2)) = -3/3 = -1

(notice I could have done:
(8-5)/(-2 - 1) = 3/-3 = -1 to get the same result )