Try Now $1$ Find the following indefinite integrals.

$($a$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}{x}^6(x^{7}6{)}^{11}dx$

$($b$){\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}si{n}^{4}xcosxdx$

Example $2$ Find the indefinite integral.

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{x}{\sqrt[\phantom{2}]{x2}}dx$