Question

What is the average rate of change from x=-2 to x=1 of this function f(x)=x^2+5x-12

Answer 1

We will first find substitute x = -2 into the function and then evaluate

f(-2) = (-2)² + 5(-2) - 12

= 4 - 10 - 12

= -18

Then substitute x = 1 into the function

f(1) = 1² + 5(1) - 12

=1 + 5 - 12

= -6

Then

Use the formula;

`(y_2-y_1)/(x_2-x_1)\text{ =}(f(b)-f(a))/(b-a)`

`=(-6+18)/(1+3)`

`=(12)/(4)`

= 3