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?:p

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- Nov 26th 2007, 05:54 AMpartyshoesConvergence 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?:p - Nov 26th 2007, 09:21 AMThePerfectHacker
$\displaystyle \left| \frac{\cos n}{n^3} \right| \leq \frac{1}{n^3}$