# Find the sum of the infinite series #-ne^(1-n)# from #n=1# to #oo#?

##### 1 Answer

Mar 5, 2018

#### Explanation:

The simplest solution I can think of starts with the infinite geometric series

which converges for

Differentiating both sides with respect to

Substituting

**Alternative**

We can evaluate the sum by a purely algebraic approach as well:

Subtracting, we get

This immediately gives the answer