$\cot g^2\left(a\right)=\cos^2\left(a\right)+\left(\cot g\left(a\right).\cos\left(2\right)\right)^2$

$\frac{x^6-1}{x-1}$

$\frac{120}{-60}$

$\frac{3ab^2}{\sqrt{c}};\:a=1;\:b=2;\:c=\frac{1}{4}$

$-3x^2+x+2\cdot6x+10$

$\lim_{x\to0}\left(\frac{1-\ln\left(b\right)}{1+\ln\left(b\right)}\right)^x$

$\lim_{x\to-4}\frac{x^2-15}{x^2-16}$