Thread: Finding value of x for which series is convergent

1. Finding value of x for which series is convergent

Hi,

I'm not sure how to solve this question.

2. Re: Finding value of x for which series is convergent

Sorry I have to post a small picture, I don't know how to type math symbols on this forum. And thanks in advance.

3. Re: Finding value of x for which series is convergent

Originally Posted by verasi
Hi,

I'm not sure how to solve this question.
There's a problem. I presume that your summation is this:
$\displaystyle \sum_{x = 1}^{\infty} (x + 1)$

x here is a dummy variable, which means that you can't pick out an x for this to be true. The sum does not depend on x.

As far as LaTeX is concerned, we have a forum for that. See here.

-Dan

4. Re: Finding value of x for which series is convergent

Yah when I look at this question I was really confused. I'm not sure if my teacher wanted me to put in an expression or something. It was written as {(x+1)} superscript infinity subscript 1, but I'm assuming that means the same thing as what I typed in the original post.

Also, thanks for telling me how to type equations. I can't figure out how to type superscript and subscript on top of each other. Sorry

5. Re: Finding value of x for which series is convergent

Originally Posted by verasi
Yah when I look at this question I was really confused. I'm not sure if my teacher wanted me to put in an expression or something. It was written as {(x+1)} superscript infinity subscript 1, but I'm assuming that means the same thing as what I typed in the original post.

Also, thanks for telling me how to type equations. I can't figure out how to type superscript and subscript on top of each other. Sorry

$$\sum\limits_{k = 1}^\infty {\left( {x + 1} \right)}$$ gives $\displaystyle \sum\limits_{k = 1}^\infty {\left( {x + 1} \right)}$
Click on the “go advanced” tab. On the toolbar you will see $\displaystyle \boxed{\Sigma}$ clicking on that give the LaTeX wraps, . The code goes between them.

This series converges for only one value if x, $\displaystyle x=-1$.
$\displaystyle \sum\limits_{k = 1}^\infty {\left( {x + 1} \right)}$

Could that be what was meant?

6. Re: Finding value of x for which series is convergent

I think that's what it means. Thanks for the answer