$\lim_{t\to1}\left(\frac{sen\left(\pi t\right)}{lnt}\right)$

$\frac{d}{dx}\left(\frac{1+\sin\left(x\right)}{x\cdot\cos\left(x\right)}\right)$

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

$\left(\frac{3^{-1}ab^{-9}}{5^{-1}a^{-3}b-12c}\right)$

$z^2-12z+20$

$2x^2+3xy^2+2x^3y$

$12x^2,-2x^2,4x^2$