Math Is Fun Forum

aidan

Member

Registered: 2010-10-15

Posts: 5

convert summation into equation

Hai,

I have a problem on how to get the equation for the following summation:

∑ {[ xi^(-δ) ] ÷[ 1+ γ*xi^(-δ) ]}

where:
the summation started from i=0 to n,
δ and γ are constant

Last edited by aidan (2010-10-15 16:55:14)

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert summation into equation

Hi aidan;

Welcome to the forum. I can not see what that series is.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

aidan

Member

Registered: 2010-10-15

Posts: 5

Re: convert summation into equation

I'm new here. That was the coding form. I try to figure out how to make the equation appear as it should be.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert summation into equation

Hi;

You can use latex:

http://www.mathisfunforum.com/viewtopic.php?id=4397

Or you can write it on paper and scan it and upload it as an image.

Or you can go here which will latex it for you somewhat.

http://latex.codecogs.com/editor.php

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

aidan

Member

Registered: 2010-10-15

Posts: 5

Re: convert summation into equation

aidan

Member

Registered: 2010-10-15

Posts: 5

Re: convert summation into equation

ok that is the summation. I have the problem on how to convert that summation into an equation.

  are constant

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert summation into equation

The sum can be simplified to:

Beyond that there is not much to be done with it. You are summing in terms of i which is a subscripted variable. Unless the problem is incorrectly copied or you want something else done with it, I think that is it.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

aidan

Member

Registered: 2010-10-15

Posts: 5

Re: convert summation into equation

The summation lies within the equation:

I need to take out the summation symbol so that I can express

are the parameters. I fix

, so that I can express 

.

Did the above explanation lead to different answer? If no, I just refer to your previous answer.

Anyway, thanks a lot, I appreciate it

Last edited by aidan (2010-10-15 18:13:05)

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: convert summation into equation

Hi Aidan;

I understand you want to eliminate the summation, this is called evaluating or doing the sum. Please remember sums are like integrals most of them do not have answers in terms of elementary functions. Meaning most of them can not be done.

Yours is impossible because it is going to lead to something like this.

Which means you are trying to sum n different variables to some power when I know nothing about the

In order to sum this I need to know what they are or how they are related to each other.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.