$\frac{dx}{dt}=\frac{\left(t^3-t\right)}{x}$

$\lim_{x\to2}\left(\frac{\tan\left(x\right)}{\tan\left(3x\right)}\right)$

$12z^2-7z-12$

$\int_{x-1}^{\sqrt{x}}3x+2x^2-5dx$

$\frac{d}{dx}\left(y\right)+\frac{3y}{x}=6x^2$

$\frac{dy}{dx}=ye^{3x},y\left(0\right)=3e$

$\frac{d^2}{dx^2}\left(\arctan\left(\sin\left(3x\right)\right)\right)$