Why is the series \(\sum \frac{-1}{n}\) divergent like the harmonic series?

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SUMMARY

The series \(\sum \frac{-1}{n}\) is divergent, paralleling the divergence of the harmonic series \(\sum \frac{1}{n}\). This conclusion is drawn from the fact that if the partial sums of the harmonic series diverge, then the partial sums of the negative series also diverge. The negative sign does not affect the divergence property of the series, as it merely reflects the values without altering their behavior towards infinity.

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Homework Statement



I know that the harmonic series is divergent.But why \frac{-1}{n} is also divergent?
I've search for some test to test that, but I could not find a method for negative series.
So how can I prove the series is divergent?:confused:

Homework Equations





The Attempt at a Solution

 
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haha1234 said:

Homework Statement



I know that the harmonic series is divergent.But why \frac{-1}{n} is also divergent?
I've search for some test to test that, but I could not find a method for negative series.
So how can I prove the series is divergent?:confused:

Homework Equations



The Attempt at a Solution

\displaystyle (-1)\cdot\sum_{n=1}^\infty \left(\frac{1}{u}\right)=\sum_{n=1}^\infty \left(-\frac{1}{u}\right)
 
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haha1234 said:

Homework Statement



I know that the harmonic series is divergent.But why \frac{-1}{n} is also divergent?
I've search for some test to test that, but I could not find a method for negative series.
So how can I prove the series is divergent?:confused:

Homework Equations





The Attempt at a Solution


If the partial sums of ##\sum\frac 1 n## diverge, then so do the partial sums of ##\sum -\frac 1 n=-\sum\frac 1 n##.
 

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