$\frac{d^2y}{dx^2}=4\left(1+3x\right)^2$

$\frac{dy}{dx}=\frac{1-y}{2+x}$

$\lim_{x\to\infty}\left(3^xsin\frac{5}{3^x}\right)$

$\int\frac{x}{\sqrt{16-x^4}}dx$

$\:\left(7y^2+7\right)\left(7y^2-7\right)$

$\:4h\:-\:8h\:-\:2h$

$\int\left(\frac{2x-3x^2+5}{x^2-x^3+5x}\right)dx$