+0  
 
0
110
2
avatar

Find the sum: 

\(\[\frac{1}{3^1} + \frac{2}{3^2} + \frac{3}{3^3} + \cdots + \frac{k}{3^k} + \cdots \] \)

 Feb 28, 2020
 #1
avatar
+1

∑[ n / 3^n, n, 1, ∞ ] = the sum converges to 3 / 4

 

Here is the “Partial Sum Formula”, if you wish to check it for yourself.

 

 1/4 * 3^(-m) * (-2 m + 3^(m + 1) - 3)

 Feb 28, 2020
 #2
avatar+30663 
+4

You can also do this as follows:

 

 Feb 29, 2020

21 Online Users

avatar
avatar
avatar