# Symbol questions><

1. Feb 28, 2006

### SimpleHarmonicMotion

I got some questions on symbols i've seen in formulas and equations.
What does the greek letter E mean? I see it with letters underneth it sometimes, what do they do?

There's a symbol that's a foward slash, it has letters on each end sometimes and it's most of the time in front of the = sign

2. Feb 28, 2006

### ranger

Last edited: Feb 28, 2006
3. Feb 28, 2006

### chroot

Staff Emeritus
If you can provide some examples of the equations -- with a link, perhaps -- we can try to explain to you what they mean.

The meaning of a particular mathematical notation depends heavily upon its context. The greek letter gamma, for example, might mean any of a couple of dozen different things, depending upon whether you're studying relativity, or communications theory, or something else.

Without knowing the context of where you saw these equations, we really can't help you understand them.

- Warren

4. Feb 28, 2006

### z-component

Maybe the OP means the capital greek letter sigma, since it's commonly mistaken for the greek E.

$$\sum$$

In mathematics, this symbol means summation. It is often seen with something like k=1 underneath and a single number or variable above, followed by an algebraic expression. In physics, it's also used as the "sum of" symbol, such as the sum of the forces in the x direction can be written as $$\Sigma F_x$$. http://en.wikipedia.org/wiki/Summation

5. Feb 28, 2006