$\frac{cos^4\left(\theta\:\right)\:\:\:-sin^4\left(\theta\:\right)}{cos^2\left(\theta\:\right)}=1-tan^2\left(\theta\:\right)\:$

$\int x\left(e^{5x+2}\right)dx$

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

$\lim_{x\to9}\:\frac{\left(cos\left(\pi\:x\right)+1\right)}{\sqrt{x}-3}$

$\frac{1}{2}\cot\left(\frac{x}{2}\right)-\frac{1}{2}\tan\left(\frac{x}{2}\right)$

$\sin\left(4b+5\right)$

$\left(2x^2y^{-5}\right)\left(6x^{-3}y\right)\left(\frac{1}{3}x^{-1}y^3\right)$