$\lim_{x\to0}\left(\frac{1}{2x^2}\right)$

$\frac{dy}{dx}+y\tan\left(x\right)-\sin\left(2x\right)=0$

$6x^2+36$

$\frac{dx}{dy}\cdot cosx=\frac{y}{lny}$

$2\log\left(y\right)-3\log\left(x\right)=1$

$2\pi^2+4\pi^2y$

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