$\lim\:_{h\to\:0}\frac{\left(sqrt\left(x+h\right)-sqrt\left(x\right)\right)}{h}$

$a^4-11a^3+24a^2$

$x\cdot\cos\left(x\right)\cdot dx+\left(1-6\cdot y^5\right)\cdot dy=0$

$\frac{1+cos2x}{cosx}+ctgx.senx$

$\lim_{x\to0}\:\left(\frac{sen\:20x}{sen\:2x}\right)$

$16x^2+11x+2$

$9x^4-60x^2+100$