$\lim_{x\to0}\left(\frac{\left(\sqrt{3y+1}-1\right)}{y}\right)$

$\frac{dy}{dx}+\frac{2y}{x}=\frac{\sin\left(x\right)}{x}$

$b-5-11b$

$\int\frac{1}{\left(2\cdot senx+sen2x\right)}$

$\frac{d}{dx}\left(7x^{4x}\right)$

$2x\sin\left(a\right)+2x^2\cos\left(a\right)$

$3y^2-4y-4$