Question

Find the average rate of change for f(x)=x^2-3x-10 from x=-5 to x=-10

Answer 1

-18

Explanation:

f(x) = x² - 3x -10

f(-10) = (-10)² – 3(-10) – 10

f(-10) = 100 + 30 - 10

f(-10) = 120

f(-5) = (-5)² – 3(-5) – 10

f(-5) = 25 + 15 - 10

f(-5) = 30

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The average rate of change is the slope m of the straight line joining the two points.

m = (y₂ - y₁)/(x₂ - x₁)

m = (30 - 120)/(-5 – (-10))

m = -90/(-5+10)

m = -90/5

m = -18