$\lim_{x\to\infty}\:\left(\frac{\sqrt{x^2+2}}{\sqrt{2x^2+1}}\right)$

$y''+5y'+4y=0\:,\:\:y\left(1\right)=0\:y'\left(1\right)=2$

$x^3-5x^2-9x+45$

$4x-2y$

$4+x^4+4x^2$

$16x^2-6x^3$

$\int_{\frac{l}{2}}^{\frac{3l}{4}}\left(\frac{2}{l}sen^2\:\left(\frac{4\pi x}{l}\right)\right)dx$