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Homework Help: Integration (Related to Physics)

  1. Feb 18, 2008 #1
    [SOLVED] Integration (Related to Physics)

    This shouldn't take long :smile:

    I have been given the general equation for a straight line which is:

    [tex]y=mx+c[/tex]

    Now I know that to determine the gradient I can use:

    [tex]m=\frac{y}{x}[/tex]

    Here is my question. Can I differentiate the initial equation given to get to [tex]m=\frac{y}{x}[/tex]

    If so, which I am sure you can, then I seem to have come across a problem, though I think it is a problem in my differentiation.

    [tex]y=mx=c[/tex]

    [tex]\frac{dy}{dx}=mx^{-1}[/tex]

    [tex]m=\frac{y}{x^{-1}}[/tex]

    or

    [tex]m=\frac{x}{y}[/tex]

    This does not agree with my initial statement. Either my differentiation is incorrect or I need to touch up on my laws of indices, and if neither of these maybe I am deluded and this can't be done anyway :tongue:

    _Mayday_
     
  2. jcsd
  3. Feb 18, 2008 #2

    Doc Al

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    Staff: Mentor

    (1) The slope is given by [itex]m = \Delta y / \Delta x[/itex], not [itex]m = y/x[/itex].
    (2) The derivative (with respect to x) of mx + c is just m.
     
  4. Feb 18, 2008 #3
    Just noticed the thread title is integration not differentiation. Thank you for your help.
     
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