$y'=xe^{x^2}$

$\left(\csc\left(x\right)-\sin\left(x\right)\right)\sec^2\left(x\right)$

$\log_{20}\left(x\right)+\log_{20}\left(x-1\right)=1$

$\lim_{x\to0}\left(\frac{x+1}{x+3}\right)^{\frac{1}{x}}$

$5-\left(18-105\right)$

$\lim_{x\to\infty}\left(\sqrt{4x^2+4x}-\sqrt{4x^2-x}\right)$

$\frac{1\:+\:cos\:2u}{2}$