Respuesta :

The series converges to  1/(1-9x) for -1/9<x<1/9                  

Given the series is  ∑ [tex]9x^{n} x^{n}[/tex]

We have to find the values of x for which the series converges.

We know,                

∑ [tex]ar^{n-1}[/tex]    converges to  (a) / (1-r) if r < 1

Otherwise the series will diverge.

Here, ∑ [tex](9x)^{n}[/tex] is a geometric series with |r| = | 9x |

And it converges for |9x| < 1

Hence, the given series gets converge for -1/9<x<1/9

And geometric series converges to a/(1-r)

Here, a = 1 and r = 9x

Therefore, a/(1-r) = 1/(1-9x)

Hence, the given series converges to   1/1-9x  for  -1/9<x<1/9

For more information about convergence of series, visit

https://brainly.com/question/15415793

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