$\int\left(\frac{1}{\cos\left(4x\right)}\right)dx$

$-150x^2+1500x-2150=y$

$\int xe^{-6}dx$

$\sin^2a\tan a+\cos^2a\cot a+2\sin a\cos a$

$\frac{1}{2}a+\frac{2}{3}=\frac{3}{4}a-\frac{1}{3}$

$\int\frac{1}{x^2-4x+8}dx$

$\int\frac{x^2-4x-17}{\left(x^2+1\right)\left(x-1\right)}dx$