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Homework Help: Calculate the derivative of: 8³√x

  1. Nov 10, 2006 #1
    I'm not sure how to calculate the derivative of: 8³√x :if anyone can help me or show me how to calculate the derivatives of similar problems such as this it would be greatly appreciated. :biggrin: Thanks

    It says in the back of the book that the answer is: 8/3³√x¹¹

    I have never done one of these problems before and this is how i tried to approach it:
    dy/dx = 8 X 1/2 ^3 x^1/2 - 1
    = 8/2^3 x^-1/2

    Thats what i kinda thought at first but it is so wrong :blushing:

    I've looked through the worked examples in the book and there are no problems like this. This is the only problem out of this section of exercises that I am having trouble with.....its really disapointing because it broke me groove :cry: and its really annoying me that I can't work it out!
  2. jcsd
  3. Nov 10, 2006 #2
    Is that 8^3 * sqrt(x), or 8 times the cubed root of x?
  4. Nov 10, 2006 #3
  5. Nov 10, 2006 #4
    i think its 8 times the cubed root of x
  6. Nov 10, 2006 #5
    Write it as 8.x^(1/3) and differentiate normally.
  7. Nov 10, 2006 #6
    cool thanks alot :D
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