Chapter 2.3, Problem 111E

In the following exercises, assume that $\underset{x\to 6}{\lim }f\left(x\right)=4,\underset{x\to 6}{\lim }g\left(x\right)=9,\text{and}\underset{x\to 6}{\lim }h\left(x\right)=6$ . Use these three facts and the limit laws to evaluate each limit.

111. $\underset{x\to 6}{\lim }\sqrt{g\left(x\right)-f\left(x\right)}$