Question

Find the average rate of change for the function over the given interval y=x^2+9x between x=3 and x=7.

Answer 1

average rate of change = 19

Explanation:

the average rate of change of f(x) in the closed interval [ a, b ] is

`(f(b)-f(a))/(b-a)`

here [ a, b ] = [ 3, 7 ] and y = f(x) , then

f(b) = f(7) = 7² + 9(7) = 49 + 63 = 112

f(a) = f(3) = 3² + 9(3) = 9 + 27 = 36

then

average rate of change =
`(112-36)/(7-3)` =
`(76)/(4)` = 19