Math Question

Discussion in 'Spam Heaven' started by Rummage, Feb 25, 2007.

  1. Rummage

    Rummage Well-Known Member

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    Can someone explain each step for this derivate y = (2x - 3)
     
  2. Lennox

    Lennox Well-Known Member

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    derivative is

    y` = 2

    You just use the power rule.
    So 2x is really saying 2x^1
    Take that power of 1, and times it by 2. Now where the power used to be, minus 1 from it, so you get 0. 2x^0 is actually 2.

    So lets say we have 4x^3
    Times 4 by the 3. Then for the power, go 3-1.
    So we get 12x^2
     
  3. Rummage

    Rummage Well-Known Member

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    Sorry m8, wrong question right one is y = (2x - 7) ^ 3

    ^ 3 = cubed

    Sorry >_>
     
  4. Marforce

    Marforce Senior Member

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    Chain Rule:

    y' = n([g(x])]^n-1 * d/dx[g(x)]

    Thus:

    Let u = 2x-7
    du/dx (derivative of u)= 2

    Therefore: 3(u)^3-1 * du/dx
    = 3u^2 *2
    =6u^2
    But u = 2x-7

    therefore y' = 6(2x-7)^2

    Hopefully did enough steps for you, 99% of the time it's unnecessary to do it in this many steps.
     
  5. Rummage

    Rummage Well-Known Member

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    Dang It, I knew it I was absent the day we went over the chain rule, thanks Marforce. And I need all the steps xD, I need to under stand the chain rule
     
  6. Marforce

    Marforce Senior Member

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    NP if you need any more help let me know.

    Although typing calc. out is a pain :P
     

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