$\lim_{x\to\infty}\left(\frac{cos2x}{x^2-\pi}\right)$

$\ln\left(\sqrt[3]{x^2-2x-15}\right)$

$\lim_{x\to\infty}\left(\sqrt{x^2-1}-x\right)$

$\left(\frac{-7a^2b^{-3}}{5a^{-4}b^3}\right)^2$

$\lim_{x\to\infty}\left(\frac{2x+1}{\:x+1}\right)^{2x-3}$

$\int x\sqrt{1+4x^2}dx$

$12x^3:3x^8$