$\lim_{x\to1}\left(\frac{e^x-\left(1-x\right)}{x}\right)$

$\lim_{x\to\infty}\left(\frac{1}{x^2}-\frac{1}{x^2\sec\left(x\right)}\right)$

$\frac{dy}{dx}=12x^3$

$3xy+6z+10-\left(9-9yx-10z\right)$

$\int\frac{9}{x^2-4x-5}dx$

$x+4\left(x^4+2x^3-7x^2+5x+12\right)$

$\cot\left(x\right)\left(\sin\left(x\right)+\sin\left(2x\right)\right)$