$\frac{\sin\:2\:\theta-\cos\:\theta}{1-\sin\:\theta-\cos\:2\:\theta}=\cot\:\theta$

$3.\frac{1}{27}^6.1$

$\frac{1}{\sin^2\left(x\right).\cos^2\left(x\right)}=\frac{1}{\sin^2\left(x\right)}+\frac{1}{\cot^2\left(x\right)}+1$

$\int\left(\frac{-43e^x-196}{e^{2x}+11e^x+28}\right)dx$

$xy^2\left(\frac{dy}{dx}\right)+1=y$

$2-1-3+2+5-3$

$850-1070$