# Evaluating Sums?

• 09-26-2010
matthayzon89
Evaluating Sums?
Hello,
I am currently working on a practice program in which I need to evaluate finite sums.

Before I get to coding this, I need to understand how to do it on paper...

Can someone please show me how I would go about evaluating this for example:

2n
E i
i=5

Step by step would appreciated b/c I am quite new to this whole concept.

• 09-26-2010
Char*Pntr
Quote:

Originally Posted by matthayzon89
Hello,
I am currently working on a practice program in which I need to evaluate finite sums.

Before I get to coding this, I need to understand how to do it on paper...

Can someone please show me how I would go about evaluating this for example:

2n
E i
i=5

Step by step would appreciated b/c I am quite new to this whole concept.

It's been a while since I've been in HS. I think the sum reduces to: n(2n + 1) with
index i =1. (you have an offset 5)

Before I go on, are you asking for help with the mathematics? If not, post the code
that you have at this point.
• 09-26-2010
matthayzon89
Quote:

Originally Posted by Char*Pntr
It's been a while since I've been in HS. I think the sum reduces to: n(2n + 1) with
index i =1. (you have an offset 5)

Before I go on, are you asking for help with the mathematics? If not, post the code
that you have at this point.

Yes, I am working on the program. But I would like to understand how to work out the mathematics first, before I actually code up the problem.

I appreciate your help man. It is really important that I understand this. I will most definitely study the explanation you will give, and would appreciate it if you can break it down to steps.
• 09-26-2010
Char*Pntr
Quote:

Originally Posted by matthayzon89
Yes, I am working on the program. But I would like to understand how to work out the mathematics first, before I actually code up the problem.

I appreciate your help man. It is really important that I understand this. I will most definitely study the explanation you will give, and would appreciate it if you can break it down to steps.

I was hoping to help you get started, I still don't see any code yet. :confused:

Since now this is a case of understanding the mathematics, this should have been
posted in perhaps the General Discussion board.. np as this thread will probably be
moved there anyway.

I'm sorry, I can't as this is now completely off topic. This will only cause irritation to
the regulars here, and rightly so.
• 09-27-2010
nonoob
Seems to me to be simple summation of i... up to 2n.

So if n=6, i must reach 12 for the sequence to stop.

answer is 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12