Math Is Fun Forum

John@comp

Guest

How does this summation work?

Hello all! I've decided to go try to get a degree in computer engineering and have little experience in math past high school algebra II. That's right guys, I have stepped in it and it does not smell good!

So what I'm looking at is a summation symbol with stopping point for the summation or the upper limit of summation in a position that makes it look like it is in the power position (@ one o'clock from the summation symbol) and index of summation is off to the lower right hand side (@ five o'clock from the summation). Does this still behave in the normal fashion?

Additionally I'm looking for a quick reference for values and characters that show up at various points around a summation or similar notation (like an "e" symbol in a seven o'clock potion).
This is all in relation to harmonic and weighted harmonic means used in computer architecture and organization. I'm using Stallings, William. Computer Organization and Architecture  and this issue comes from p. 64 if that helps anyone help me out.

Thanks in advance for all your help and consideration.

V/r
John

Bob

Administrator

Registered: 2010-06-20

Posts: 10,640

Re: How does this summation work?

hi John@comp

Welcome to the forum.

Not quite sure what you're asking for.

It sounds a bit like sigma notation.  You'll find a little about it here:

https://www.mathsisfun.com/algebra/sigma-notation.html

Here's how you can use the forum maths notation to make a display for what you're wanting:

Here's what I typed to get this:

\sum^5_1{n^2} = 1 + 4 + 9 + 16 + 25

To make the LaTex work you need the command 'square brackets' math at the start and square brackets /math at the end of your LaTex.  I should have been able to display this using another bcCode command square brackets code but it seems to have stopped working properly on my laptop (maybe on the forum too)
 

Let's get a dialogue going so I can properly help.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob