# How do you determine if the series the converges conditionally, absolutely or diverges given #Sigma (cos(npi))/(n+1)# from #[1,oo)#?

##### 1 Answer

Apr 1, 2017

#### Explanation:

Since

Let us see if it is absolutely convergent.

which is a harmonic series (divergent). So, it is NOT absolutely convergent.

Let us see if it is conditionally convergent.

Since

Hence, the series is conditionally convergent.