$\lim_{x\to infinito}\left(\frac{x\cos\left(x\right)}{1-cos\left(x\right)}\right)$

$\left(x-1\right)^2+\left(x-1\right)\cdot\left(x+1\right)$

$4^3\cdot4^3\cdot5$

$\frac{3x}{4}-2\ge10$

$\tan\left(\frac{x}{2}\right)-\cot\left(\frac{x}{2}\right)=-2cot\left(x\right)$

$\tan\left(360-x\right)$

$-55\left(0\right)$