Chapter 8.5, Problem 12E

a.

To determine

To find: The expression for $\frac{f\left(x+h\right)-f\left(x\right)}{h}$ if $f\left(x\right)=12-2x^2$.

b.

To determine

To explain: The value for $\frac{f\left(x+h\right)-f\left(x\right)}{h}$ if h becomes very close to 0.