# Math Help - Infinite Series Convergence

1. ## Infinite Series Convergence

Hi folks,

Please comment on how to proceed with finding whether the following series converge or not:
$1+\frac{1}{2}+\frac{1}{3}-\frac{1}{4}-\frac{1}{5}-\frac{1}{6}+\frac{1}{7}+\frac{1}{8}+\frac{1}{9}-\frac{1}{10}\text{--}\text{++}+\text{--}-$

Thanks a lot.

Max.

2. ## Re: Infinite Series Convergence

Originally Posted by MaxJasper
Please comment on how to proceed with finding whether the following series converge or not:
$1+\frac{1}{2}+\frac{1}{3}-\frac{1}{4}-\frac{1}{5}-\frac{1}{6}+\frac{1}{7}+\frac{1}{8}+\frac{1}{9}-\frac{1}{10}\text{--}\text{++}+\text{--}-$
This is only a comment or suggestion. Let
\begin{align*}s_1&=\frac{1}{1}+\frac{1}{2}+\frac{1 }{3} \\ s_2&=\frac{1}{4}+\frac{1}{5}+\frac{1}{6} \\&\vdots \\ s_n&=\frac{1}{3n-2}+\frac{1}{3n-1}+\frac{1}{3n}\end{align*}

Now your series is $\sum\limits_{n = 1}^\infty {{{\left( { - 1} \right)}^{n + 1}}{s_n}}$.
Does the alternating series test apply?

3. ## Re: Infinite Series Convergence

What a beauty! Thanks a lot bro...very simple and nice.

4. ## Re: Infinite Series Convergence

Had a response, but Plato's solution is very nice.