$\arctan\left(e^{-\infty}\right)$

$\left(20\right)^4$

$\frac{x^3+y^3}{\sqrt[5]{x^3+1}+2x-1}$

$\left(\sin\left(x\right)\right)^4-2\left(\sin\left(x\right)\right)^2+1=0$

$\left(x^2+1\right)y'+\left(4xy\right)=x$

$\int_{-\infty}^1\frac{3x^3+5x}{x^2+1}dx$

$-3h^2-90h-675$