Properties of Functions & The Average Rate of Change

Question

Let h(x)=x²-4x

A) Find the average rate of change from 7 to 8

B) Find an equation of the secant line containing (7, h(7)) and (8, h(8))

Answer 1

h(7) = 49 - 28 = 21 Pt: (7 , 21)

h(8) = 64 - 32 = 32 Pt: (8 , 32)

Avg. r.o.c. on the interval [7 , 8] = m = (32 - 21) / (8 - 7) = 11

Pt-Slope form of eqn. of secant line: y - 21 = 11 (x - 7)

Slope-Int. form: y = 11x - 56