$\sqrt{a}^2-u^2$

$\frac{-12x^4+7x^3-5}{x-6}$

$36-49z^8$

$\int\sin\left(4x\right)\:\sin\left(3x\right)\:dx$

$\left(\frac{\left(x^{-3}y^{-1}z^2\right)^{\frac{1}{2}}\left(x^2y^4\right)^{\frac{1}{3}}}{\left(x^{-2}y^{-3}z^{-1}\right)^{-1}}\right)$

$\frac{d^2}{dx^2}\left(3x-x^2\cos\left(x\right)\right)$