Typos in the paper

[trunghng]

Hello. Thanks for sharing this amazing work. I believe there are some typos in paper. In particular, in the equation (13), the derivative $\frac{\partial P(x)}{\partial x}$ should be $\frac{\partial P(x)}{\partial x}=a_1+2a_2x+\ldots+ma_mx^{m-1}$. Same goes for the derivative $\frac{\partial Q(x)}{\partial x}$.