$\int\left(\frac{f}{\sqrt{25-f^2}}\right)df$

$x^2+2x-x-2$

$k2-25$

$\left(5x^4+6y^2\right)\cdot\left(25x^8-30x^4y^2+36y^4\right)$

$\int\left(x^{-4}+4x^{-3}-2x^{-2}+3x^{-1}\right)dx$

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

$\lim_{x\to0}\left(\frac{xy^2}{x^2+y^4}\right)$