Activity 5.5.3

For each of the following integrals, evaluate the integral using $u$-substitution and/or an entry from the table found in Appendix.

1. $\displaystyle \int \sqrt{x^2 + 4} \, dx$

2. $\displaystyle \int \frac{x}{\sqrt{x^2 +4}} \, dx$

3. $\displaystyle \int \frac{2}{\sqrt{16+25x^2}}\, dx$

4. $\displaystyle \int \frac{1}{x^2 \sqrt{49-36x^2}} \, dx$