1 I need to know the convergence of this series
$\displaystyle \sum_{k=1}^{\infty} \frac{2k+5}{\sqrt{3{k^3} - 1/2}}$
2 I have to obtain the expression of dy/dx for the following function
3xy - 2x^2y + y^3 =0
3 $\displaystyle 5x^2 + 3y^2 = 16$
The x radius is $\displaystyle \sqrt{5}$ ?
Thanks