divergence

• May 4th 2010, 03:46 PM
alexandrabel90
divergence
prove that the series 1+1/4+1/7+1/10... diverges.
• May 4th 2010, 03:49 PM
dwsmith
Quote:

Originally Posted by alexandrabel90
prove that the series 1+1/4+1/7+1/10... diverges.

Have you written the the formula that produces this series?

$\frac{1}{1}+\frac{1}{4}+\frac{1}{7}+...=\sum_{n=1} ^{\infty}\frac{1}{3n-2}$
• May 4th 2010, 05:09 PM
mr fantastic
Quote:

Originally Posted by dwsmith
Have you written the the formula that produces this series?

$\frac{1}{1}+\frac{1}{4}+\frac{1}{7}+...=\sum_{n=1} ^{\infty}\frac{1}{3n-2}$

I'll just add that it should now be clear that an appropriate test can be used.