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

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

$\left(3x+4y\right)\left(3x+5y\right)$

$e^x+e^y\:\frac{dy}{dx}\:=\:0$

$\left(a^3-\frac{1}{4}\right)^2$

$\int4x^3\left(1-x^4\right)^5dx$

$\int \frac { x d x } { x ^ { 2 } - 3 x - 4 }$