$\lim_{n\to\infty}\left(n\pi arctan\left(\frac{1}{en}\right)\right)$

$x^2-12x+3$

$\int\frac{1-\sqrt{x}}{\sqrt{x}}dx$

$\int\frac{x^2-x+1}{\left(x+4\right)\left(x-2\right)}dx$

$\int\:\frac{t-2t^4}{\sqrt{t}}dt$

$5x^{4}-3y-3x^{2}-30x+2x-2$

$\frac{d}{dx}\left(y=\frac{7x^5-2x^2}{6x^3+8x}\right)$