$2+2sen^2\theta\:=4sen^2\theta\:+2cos^2\theta\:$

$\lim_{x\to\frac{\pi}{2}}\left(\frac{5\cos\left(5x\right)-\cos\left(x\right)}{-\sin\left(5x\right)}\right)$

$f^2+3f+18$

$5\sqrt{x^3}$

$\sqrt{243}$

$\frac{b}{b^{-7}}$

$\frac{\left(cos\left(x+h\right)-cos\left(x\right)\right)}{h}$