Question

find the average rate of change over the interval [-1,2] (from x = -1 to x = 2) for the graph below

What is the coordinate where x=-1 ?

What is the coordinate where x=2?

What is the rate of change between those two points?

Answer 1

Hello!

Find the coordinate where x = -1:

At x = -1, y = 1, so the coordinate is (-1, 1).

Find the coordinate where x = 2:

At x = 2, y = -2, so the coordinate is (2, -2).

Find the rate of change between the points using the slope formula:

$slope = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

Plug in the coordinates above:

$slope = \frac{-2-1}{2-(-1)}$

Simplify:

$slope = \frac{-3}{3} = -1$

Thus, the rate of change between the points is -1.