$-2a+b^2-\frac{1}{3}a$

$\int\left(5x-3x^2-x^3\right)\left(x+2\right)dx$

$\frac{1}{2}x+\frac{1}{4}x$

$\frac{\cos^2\left(x\right)-\sin^2\left(x\right)}{\sin\left(x\right)}$

$\int_{-1}^1e^{-2x}dx$

$\cos\left(x\right)\csc\left(x\right)=\cot^2\left(x\right)$

$y_{1}\left(x\right)=\cos x;yz\left(x\right)=\senx;y_{3}\left(x\right)=1$