$\frac{1-x^3}{1+x}$

$\lim_{x\to0}\left(\frac{6\cos\left(x\right)}{x^2}\right)$

$\lim_{x\to3}\left(\frac{1-x}{x^2-4x+3}\right)$

$\int\left(4sec^2\left(2x\right)tan\left(2x\right)\right)dx$

$2x\cdot\left(x-3\right)+3\cdot\left(x^2-5\right)$

$\int\left(8e^{cost}sint\right)dx$

$\int\frac{u^5}{u^3+1}du$