$\int\frac{x^2}{\sqrt[2]{4-x^2}}ydx$

$y=\frac{1}{4}ln\left(\frac{x^2}{x^2-4}\right)-\frac{1}{x^2-4}$

$\lim_{x\to0}\left(\frac{sin^2\left(x\right)+2\cos\left(x\right)}{cos^2\left(x\right)-xsen\left(x\right)}\right)$

$196b^2a^4-225m^{12}$

$\int_{-3}^3\left(2x^2-3\right)dx$

$\frac{\left(a^4-6a^3+2a^2+3a-4\right)}{\left(a^2-a+2\right)}$

$9x^2+169x^2+49$