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

$\left(x-20\right)+\left(x-3\right)$

$\sqrt{9x^2}y^6$

$tanacos^2a$

$4-5-2x-4y+4-5x+7y$

$\int\left(1+16\cos\left(x\right)^2\right)dx$

$\int_2^6\left(\frac{x}{\sqrt{5x^2+1}}\right)dx$