$y=\frac{1}{2}x^2-x-4\:;\:x=-2$

$\frac{600}{x^2+300}<500$

$\frac{dy}{dx}+4y=\frac{\left(\sqrt{2}-2\right)}{3}e^x$

$\frac{dy}{dx}+3xy^3=0\:\:y\left(0\right)=1$

$\frac{1}{\frac{1+v}{1-v}-v}dv=\frac{1}{t}dt$

$sin^3\left(a\right)+\:sin\left(a\right)cos^2\left(a\right)$

$\int\frac{x^2+x-3}{x-1}dx$