$\int\sin\left(x\right).\sin\left(ax\right)dx$

$\sqrt[4]{\frac{1}{x}}$

$\frac{dy}{dx}=\frac{1}{5}\cdot\frac{y}{x}$

$\frac{a}{3\sqrt{2}}$

$4x\:+\:8x\:+\:2x$

$\lim_{x\to7}\left(\frac{\left(x^3-4x^2-22x+7\right)}{x^2-13x+42}\right)$

$\lim_{x\to\infty}\left(\frac{3x^3}{9-x^2}\right)$