$\lim_{x,y\to0,0}\left(\frac{1}{x^2y^2}\right)$

$cosx\:=\:\frac{4}{5}$

$\left(\frac{7}{9}a^{2}b^{2}c-9abc-4c\right)\left(\frac{2}{3}b^{2}c\right)$

$\lim_{x\to-1}\left(x^2+3\right)$

$f ( x ) = 2 ( 13 - x ^ { 4 } )$

$\int\frac{x^2-3x-2}{x^2\left(x+1\right)}dx$

$16x^3-x^2$