Question

Question is in the image. I need help with #19

Answer 1

EXPLANATION

Replacing the given functions into the following:

$\frac{f(x+h)-f(x)}{h}$$\frac{x^2-1+h-(x^2-1)}{h}$

Removing the parentheses and simplifying:

$\frac{x^2-1+h-x^2+1}{h}$

Simplifying like terms:

$\frac{h}{h}=1$

Hence,

$\frac{f(x+h)-f(x)}{h}=1$