## Calculus (3rd Edition)

(a) 16 (b) $\frac{1}{4}$ (c) 12
Using the basic limit laws, we have (a) $\lim\limits_{x \to 6}f(x)^{2}=(\lim\limits_{x \to 6}f(x))^{2}=4^{2}=16$ (b) $\lim\limits_{x \to 6}\frac{1}{f(x)}=\frac{1}{\lim\limits_{x \to 6}f(x)}=\frac{1}{4}$ (c) $\lim\limits_{x \to 6} x\sqrt {f(x)}=(\lim\limits_{x \to 6}x)(\sqrt {\lim\limits_{x\to 6}f(x)})$$=6\times\sqrt 4=12$