What do symbols in equations mean?

[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

 

[ranger]

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?

Thats the permittivity of free space - Epsilon zero $$\epsilon$$
http://everything2.com/index.pl?node_id=779835
http://en.wikipedia.org/wiki/Permittivity_of_free_space
http://en.wikipedia.org/wiki/Epsilon

 

[chroot]

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

 

[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

 

[Mk]

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

An integral perhaps? http://upload.wikimedia.org/math/a/0/9/a093ff645ed481a57508e44795dd8ad0.png