$-\sin\left(\frac{\pi}{4}\right)x$

$\frac{tan\:\left(x\right)-cot\:\left(x\right)}{tan\:\left(x\right)+cot\:\left(x\right)}=1-2cos^2\left(x\right)$

$\frac{x\left(x+4\right)}{\left(x+3\right)^{15}}$

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

$x^2x\frac{2}{5}$

$\int\sqrt{9\:+16x^2}dx$

$\sqrt[3]{at}$