Rationalize and evaluate when $h=0: \frac{\sqrt{16+h}-4}{h}$ Rationalize and evaluate when $h=0: \frac{\sqrt{16+h}-4}{h}$ I know how to rationalize when there is a radical in the denominator (multiply by conjugate) but how do I rationalize when there is no radical?

$$\begin{align} \frac{\sqrt{16+h}-4}{h} &= \frac{\sqrt{16+h}-4}{h}\left(\dfrac{\sqrt {16+h}+4}{\sqrt {16+h}+4}\right) =\dotsb\\\\\\\\\dotsb&= \frac{(16+h)-16}{h(\sqrt {16+h}+4)} = \frac{1}{\sqrt {16+h}+4} \end{align}$$