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Is this PDA correct?

  1. May 6, 2012 #1
    Hi,

    I'm new to differential equations and I am wondering if I solved this one correctly or if it's entirely wrong. Is it a differential equation at all?

    for

    12x3 + 6x2 + 9x
    [itex]\int[/itex][itex]\frac{dy}{dx}[/itex] = [itex]\int[/itex]12x3 + 6x2 + 9x (the boundaries being 1 and 2)
    [itex]\int[/itex]dy = [itex]\int[/itex]12x3 + 6x2 + 9x
    y = [itex]\int[/itex]12x3 + 6x2 + 9x
    y = [itex]\frac{12x4}{4}[/itex] + [itex]\frac{6x3}{3}[/itex] + [itex]\frac{9x2}{2}[/itex]]
    y = [3(2)4 + 2(2)3 + 4.5(2)2] - [3(1)4 + 2(1)3 + 4.5(1)2]
    y = [48 + 16 + 18] - [9.5]
    y = [76] - [9.5]
    y = 66.5

    Thanks,
     
    Last edited: May 6, 2012
  2. jcsd
  3. May 7, 2012 #2
    Hi !

    The computation is almost entirely correct : only a mistake just at end.
    But the writing of the symbols is almost entirely wrong (See attachment)
    You have to take care of the different meanings and symbols of : Function, indefinite integral of the function and definite integral of the function.
     

    Attached Files:

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