$\frac{\sin\left(x\right)+\sin\left(3x\right)}{\sin\left(2x\right)}=2\cos\left(x\right)$

$\left(2b+3c\right)^2$

$\lim_{x\to\infty}\left(\frac{\arctan\left(x\right)}{x}\right)$

$\left(\frac{2}{3}\:+4n^2\right)^2$

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

$\frac{dy}{dx}=-y^2$

$cot\left(x\right)=-7cot\left(x\right)$