Question

Find the radius of convergence, R, of the series.
\[\sum_{n=1}^{\infty}((7x-2)^n/(n7^n))\]
Then find the interval of convergence. please help

Answer 1

when given:\[\sum a_nx_n\]
one way to find the radius of C is to take the limit of \[\lim_{n\to inf}\frac{a_nx_n}{a_{n-1}x_{n-1}}\]

Answer 2

or put n under and n+1 above; the notation is trivial as long as you have next divided by now