+0  
 
+2
98
7
avatar+278 

This problem has been bugging me for a while. There is no common ratio and I don't know if its telescopable. Help and thank you!

 

 

\(\sum_{n=1}^{\infty} \frac{n^3}{3^n}\)

 Mar 24, 2020
 #1
avatar+111321 
+1

Hey, DragonLord...if you  send this  one  to heureka he might know how to fnd the  result mathematically...he's pretty good with this kind of thing.....

 

 

cool cool cool

 Mar 24, 2020
 #2
avatar+278 
+2

Alright, CPhill! Thanks for the advice!

 Mar 24, 2020
 #3
avatar+4569 
0

I tried rewriting the bases as powers of three.

 

 

Then, I tried diving by three and multiplying the series by three

 

but it did not work.

 

 

27/27 looks very fishy, might be the key to the problem.

 Mar 25, 2020
 #4
avatar
0

Sumfor(n, 1, 10000, (n^3 / 3^n)) = 33 / 8

 Mar 25, 2020
 #5
avatar+278 
+1

I understand guest, but an answer to me is completely meaningless if there is no process or explanation on the way there.

 Mar 25, 2020
 #6
avatar+30038 
+3

As follows:

 

 Mar 25, 2020
 #7
avatar+278 
0

Thank you as well, Alan!

 Mar 25, 2020

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