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What is the difference between a parameter and a variable?

  1. Jul 30, 2010 #1
    It seems (to me) that parameters are also kind of variables in descriptions of physics. I am confused what makes a paramater different from a variable. Can anybody please explain this?
  2. jcsd
  3. Jul 30, 2010 #2
    Hi there,

    From my point of view, here are a few parameters: g=9.8m/s2, c= 300'000km/s.

    Variables are the values that you are trying to find in any model. The model bases itself on different fixed values, or parameters.

  4. Jul 30, 2010 #3
    From a mathematical point of view, a parameter is a variable that is meant to stay fixed in a certain application. For example, in middle or high school you studied the three-parameter family of functions

    f(x) = ax^2 + bx + c.

    While the three numbers a, b, c are variables, you want to think of them as fixed and let only x vary. To distinguish the roles of a,b,c on the one side and x on the other, we refer to a,b,c as parameters.
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