Question

Let f(x)=−log(4x)+5.

What is the average rate of change of f(x) from 3 to 8?

Round your answer to the nearest hundredth.

Answer 1

- 0.09

Explanation:

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Answer 2

to solve the average rate of change, use the formula of the slope:
m = ( y2 - y1 ) / ( x2 - x1 )
but first we must solve the value of the function when x = 3

f(3) = - log ( 4 * 3 ) + 5
f (3) = 3.92

solve the function when x = 8
f(8) = - log ( 4 * 8) + 5
f(8) = 3.49

so the average rate of change
m = ( 3.49 - 3.92 ) / ( 8 - 3)
m = - 0.09