Use the ratio test to find the radius of the convergence of the power series.

How do I start this? I need to find a common expression first?

2. Originally Posted by VkL
Use the ratio test to find the radius of the convergence of the power series.

How do I start this? I need to find a common expression first?
nth term is $\frac{(2n+1)x^n}{n}$

now use the ratio test, setting the limit to be less than 1