$\int\left(\frac{1}{\sqrt{16-25x^2}}\right)dx$

$\frac{\sin\left(b\right)\:}{1+\cos\left(b\right)}+\frac{1-\cos\left(b\right)}{\sin\left(b\right)}$

$\frac{dy}{dx}=\sqrt{4+2y}$

$\left(2x+5\right)\left(2x-9\right)$

$\lim_{x\to0}\left(\frac{\ln\left(ex+1\right)}{x}\right)$

$-36:-2$

$y^4+1+2y^2$