Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Any alphebet with a small n?

  1. Jan 14, 2006 #1
    any alphebet with a small n??

    does snybody knowswat is the meaning of the eqn when there is any alphebet with a small n underneath or next to it?
  2. jcsd
  3. Jan 14, 2006 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    1. Please write in English, and not in Gibberish
    2. What are you asking about? Indices like in [itex]a_{n}[/itex]?
  4. Jan 14, 2006 #3
    yaya...that's what i mean
  5. Jan 14, 2006 #4


    User Avatar
    Science Advisor

    Arildno, there are an awful lot of people here for whom English is a difficult language! Cut them a little slack.

    teng125, and alphabetical character (to make arildno happy) with a subscript n, normally, is just a way 9f distinguishing among many different values. One application is with vectors where we may label the "x","y", and "z" components of the vector a by a1, a2, a3.

    Another important application, which is likely to be what you are looking at, is to label numbers in sequences. The only difference between a sequence and a function is that the "domain" of a sequence is the positive integers: 1,2, 3, etc. A standard way to distinguish them is to use x for a "real variable" and n for a "positive integer variable". Some texts actually use a(n) for a sequence (more correctly the nth term in the sequence) but it is more traditional to use a subscript: an.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook