$\frac{cosx+sinx}{sinx}=cot\left(x\right)+1$

$\frac{dy}{dx}=\frac{sin\left(\frac{x}{y}\right)}{\left(\left(\frac{x}{y}\right)sin\left(\frac{x}{y}\right)+1\right)}$

$\lim_{x\to0}\left(\frac{2sen\left(x\right)-cos\left(2x\right)}{1-cos\left(x\right)}\right)$

$2b^5-b^3$

$\left(125\right)\left(1119\right)$

$x^3y^6=2\:$

$taylor\frac{1-e^{-x}}{x}$