SOLUTION: Is this infinite Series,convergent or divergent? 1 - 1 + 1 - 1 + 1 ...(- 1)^r - 1

Algebra.Com
Question 1009855: Is this infinite Series,convergent or divergent?
1 - 1 + 1 - 1 + 1 ...(- 1)^r - 1

Answer by ikleyn(52793)   (Show Source): You can put this solution on YOUR website!
.
It is not converged.

---------------------------------------------------------------------
Comment from student: Hi you say (- 1)^r - 1 is divergent yet (- 1)^r - 1 x b can be proved convergent if b > 0
This can be easily seen if b = 1/n...now if b = 1 the above doesn't change yet you claim it is still convergent..can you explain why?
Best wishes,thx,Colin
---------------------------------------------------------------------

My response.
1) Yes, the series {  } with the constant b, |b| < 1, is converged. It is geormetric progression,  by the way.

2) Yes, the series  is not converged. It is diverged.

These two series are different. They are not the same. Do not miss them. 
Different series have different properties. 

3) Read these two links

https://en.wikipedia.org/wiki/Convergent_series

and

http://tutorial.math.lamar.edu/Classes/CalcII/ConvergenceOfSeries.aspx
(example 3).


RELATED QUESTIONS

Determine whether the series 3 - 1 + 1/3 - 1/9 + ... is convergent or divergent. If... (answered by AnlytcPhil)
Is the following series convergent or divergent? 5+3+1+-1+... (answered by Edwin McCravy)
1/3^10 + 1/3^8 + 1/3^6 +... determine whether each series is convergent or divergent.... (answered by Fombitz)
Have I correctly labeled the below geometric series correctly? 1 + 1.2 + 1.44 + ....... (answered by ikleyn)
determine whether the integral from 1 to 9 for the function 1/cuberoot(x-9)dx is... (answered by Edwin McCravy)
I need help with my Algebra please. It says tell whether each sequence is convergent or... (answered by jim_thompson5910)
Determine if the following series are convergent of divergent. If the series is geometric (answered by KMST)
Determine if the following series are convergent of divergent. If the series is geometric (answered by KMST)
Question 1: Evaluate the limit of the following sequence... (answered by lynnlo)