Question

Find the average rate of change of f(x) = 2x2 – 7x from x = 2 to x=6.

Simplify your answer as much as possible.

Answer 1

-6

Explanation:

`\text{The average rate of change of function}\ f(x)\\\text{over the interval}\ a\leq x\leq b\ \text{is given by this expression:}\\(f(b)-f(a))/(b-a)\\\\f(x)=2x^2-7x\\\\\text{Put the values of x = 2 and x = 6 to the equation of the function:}\\\\f(2)=2(2^2)-7(2)=2(4)-14=8-14=-6\\f(6)=2(6^2)-7(6)=2(36)-42=72-42=-30\\\\(f(6)-f(2))/(6-2)=(-30-(-6))/(4)=(-24)/(4)=-6`