Q$1(10$ points$)$

We start by solving a few integration problems using substitution.

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}2xsin(-x^2)dx$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}{x}^{2}se{c}^2(x^3)e^{tan(x^3)}dx$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}tan(x)dx$