$\frac{cos^2\left(x\right)}{tan\left(x\right)}+\frac{tan\left(x\right)}{sec^2\left(x\right)}$

$\sen^{2}\left(\theta\right)-2\cos\left(\theta\right)=0$

$x^2+4x-6=0$

$\lim_{x\to0}\left(\frac{7x-sin\left(x\right)}{x^2+\:sin\left(3x\right)}\right)$

$\int\frac{x^3}{\left(6-x^4\right)^2}dx$

$y^8\cdot2^8$

$-e^1$