$\int e^{2x}cos\left(9x\right)dx$

$\:-78\:x\:22\:$

$\int\frac{x^2}{\left(x+5\right)^{\:3}}dx$

$\left(t+6\right)\left(t-8\right)$

$\frac{1-\sec^2\left(x\right)}{1-\csc^2\left(x\right)}$

$\frac{\left(2x-1\right)\left(x+1\right)}{x-1}$

$\lim_{a\to0}\left(\frac{2\sin\left(a\right)-\tan\left(a\right)}{a}\right)$