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Homework Help: Is this a graph of a delta function?

  1. Jan 25, 2007 #1
    1. The problem statement, all variables and given/known data
    My question asks me to sketch the following:
    [tex]g(x) = \delta (y+a) + \delta (y) + \delta (y-a)[/tex]

    2. Relevant equations

    3. The attempt at a solution

    I think this is it, but am I correct? I don't recall actually seeing a delta function other than a Kronicker(sp?) delta function, and I'm pretty sure that this isn't one of that type. Research on the web therefore leads me to this (because after trawling my notes I can't actually find anything about it in the entire course!).
  2. jcsd
  3. Jan 25, 2007 #2
    another delta function is such a function that integral of d(x)f(x)dx is f(0), and defined like this it cant really be plotted.
  4. Jan 26, 2007 #3


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    Science Advisor

    Well, except that those aren't infinitely tall! Actually, I don't think that is a very good question because the "delta function" isn't a true "function" and doesn't have a graph. A rough "physicist's" idea of the graph of a delta function [itex]\delta(x)[/itex] would be an infinitely high vertical line at x= 0. Since this is in "precalculus", your three (infinitely high) vertical lines at -a, 0, and a are what I would guess are intended here.
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