$9x^4-9$

$\left(x+3\right)\left(x^2-6x\right)$

$\frac{-\sin^2\left(x\right)+1-\cos\left(x\right)}{1-\cos\left(x\right)}=-\cos\left(x\right)$

$2a^2-9a+9a+4$

$\int-2\left(5x-1\right)cosh\left(-5x^2+2x-3\right)dx$

$f\left(x\right)=e^{2x-1}$

$\frac{x\sqrt{8}}{\sqrt{2}}$