$\int3x^2-2x\left(3x^3-3x^2\right)dx$

$\left(-a'\frac{\sin\left(x\right)\:}{\cos\left(x\right)}\right)\left(-\sin\left(x\right)\right)+\left(a'\:\cos\left(x\right)\right)=cscx$

$-6\cdot13-4$

$\frac{x^{12}}{x^{12}}$

$\frac{1}{2}\sin\left(2x\right)cos\left(2x\right)$

$z^2-2zy+y^2$

$\frac{5x^2}{x^3-3x^2+3x-1}$