A power series from $\frac{x}{9+x^2}$ I need to make power series from $\frac{x}{9+x^2}$, and I don't have any idea how.
The only thing I know is how to make power series from $\frac{1}{1-q}$.
Thank you!

HINT:
$$\frac x{9+x^2}=\frac x{9\left(1+\frac{x^2}9\right)}=\frac x9\left(1+\frac{x^2}9\right)^{-1} $$
now apply Maclaurin series and take care of the radius of convergence which demands $\displaystyle \left|\frac{x^2}9\right|<1$ 
