Question

For the function f(x) = –x + 21, what is the difference quotient?

Answer 1

D

Explanation:

Answer 2

The difference quotient is the quotient of the difference of the function values, f(x + h) - f(x), and the difference of the input values, (x + h) - x.

Given the function f(x) = -x + 21.

The different quotient will be :
`(f(x+h)-f(x))/((x+h)-x) =(f(x+h)-f(x))/(h) = ((-(x+h)+21)-(-x+21) )/(h) = (-x-h+21+x-21)/(h) = (-h)/(h) = -1`

We see that given the function f(x) = -x+21 and two input values of x and x + h, the difference quotient is -1.