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

$\frac{d}{dx}\left(sen\left(cos\left(sen^2\:3x\right)\right)\right)$

$-9ab\left(xa^3+ya-2\right)$

$2\:\ln\left(x+3\right)=10$

$4+8>16$

$45x+30y$

$\left(4a+5b^2\right)^2$