Chapter 8.7, Problem 19E

Preliminary work Use a table of integrals to determine the following indefinite integrals. These integrals require preliminary work, such as completing the square or changing variables, before they can be found in a table.

31. $\begin{array}{l}{\displaystyle \int \frac{e^x}{\sqrt{e^{2x}+4}}dx}\\ \end{array}$