# Math Help - Convergence test

1. ## Convergence test

Hi Folks

I need to find out if the series converges: cos n/n^3. I think it is a harmonic series becouse of the power on the denomimator but how do I combine this with sinusiodal cos n?

Has anyone ever seen this before?

2. $\left| \frac{\cos n}{n^3} \right| \leq \frac{1}{n^3}$