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

$\left(3\right)dx+e^{3x}dy=0$

$\sqrt[4]{\sqrt[2]{x^{6}}}\cdot\frac{\sqrt{x^{3}}}{\sqrt{\sqrt[3]{x}}}$

$2.6\:\cdot3$

$-sin\left(x\right)\:=\:q$

$\frac{d}{dx}\left(2x+x^2+9\right)$

$\frac{d}{dx}e^{-y}$