$\lim_{x\to0}\left(\frac{\left(x-\frac{\pi}{2}\right)\sin\left(\frac{3\pi}{2}-x\right)}{1-\sec\left(x-\frac{\pi}{2}\right)}\right)$

$-\left(-29\right)+\left(37\right)+\left(-30\right)-\left(101\right)$

$\tan\left(x\right)\:.\:\cot\left(x\right)-\cos^2\left(x\right)$

$3y\left(7xy^3-6x^2-4yz\right)$

$x^4-2x^2-6x-1-x^3-6x^2+4$

$4x^2-16xy+16y^2$

$36-8+5$