$\left(-2x^2+9\right)-\left(-2x^2-6x\right)$

$\sin\left(x\right)\sec\left(x\right)+\frac{1}{\cot\left(x\right)}$

$\frac{\sqrt{m}}{\sqrt{s}}$

$\left(156x^2+4x^2\right)$

$\frac{dy}{dx}\left(3sin\left(3x\right)\right)$

$\sqrt{16-0^2}$

$\frac{dy}{dx}=\frac{4}{x^2}-\frac{1}{x}y+y^2$