$x^3-x^2+x^{-2}-5^2$

$\int\:2e^{-2x}dx$

$x\left(\frac{\sin\left(x\right)}{\cos^2x}\right)-\left(\frac{1}{\cos\left(x\right)}\right)\tan\left(x\right)=0$

$2.14-18.675x-1.14$

$\:\frac{5x^4}{x}$

$\lim_{n\to\infty}\left(e^{-\frac{n^2+2}{3n^2+n}}\right)$

$\lim_{x\to0}\left(\frac{\ln\left(1+x\right)-x}{1-\cos\left(x\right)}\right)$