$\cot\:\:\left(90-x\right)=\frac{2\sin\:\:\left(x\right)\cos\:\:\left(x\right)}{1+\cos\:\:^2\left(x\right)-\sin\:\:^2\left(x\right)}$

$\csc^2x-2\csc x-8=0$

$\frac{dy}{dx}\left(e^{4x^2-3x+7}\right)$

$7x+8x+9\left(-3x+2\right)+12$

$\left(2x+3y\right)\left(3x-3y\right)$

$\lim_{x\to6}\left(\frac{sqrt\left(x+10\right)+4}{x-6}\right)$

$\left(2x+1\right)\left(27x^3-108x^2+144x-64\right)$