?

Free Version
Difficult

Finding the Interval of Convergence

APCALC-UPW0DJ

Find the interval of convergence for the power series $\sum _{ n=1 }^{ \infty }{ \cfrac { { \left( 3x+1 \right) }^{ n } }{ { n }^{ 2 } } }$.

A

$\cfrac { 2 }{ 3 } \ < \ x \ < \ 0$

B

$-\cfrac { 2 }{ 3 } \le \ x \ \le \ 0$

C

$-\infty \ < \ x \ < \ \infty$

D

$-1 \ < \ x \ < \ 3$