In using the technique of integration by parts, you must carefully choose which expression is $\displaystyle {u}$ . For the following problem, use the guidelines in this section to choose $\displaystyle {u}$ . Do not evaluate the integral.

$\displaystyle \int{x}^{{{6}}}{\arctan{{\left({5}{x}\right)}}}{\left.{d}{x}\right.}$

How to write your answer: If u=2x, just write 2x