$8x^2-32x+40$

$\lim_{x\to\infty}\left(1-\frac{3}{x}\right)^{3x}$

$\int\frac{2x}{\sqrt{4+x^2}}dx$

$\lim_{x\to0}\left(\frac{\sqrt{1+\tan\left(x\right)}-\sqrt{1-\tan\:\left(x\right)}}{x}\right)$

$g^2-12g$

$f\left(x\right)=\frac{x-1}{x^2-1}$

$\lim_{x\to-3}\left(\frac{x^2+6x+9}{x^2+7x+12}\right)$