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Homework Help: Implicit differentiation

  1. Apr 17, 2007 #1
    1. The problem statement, all variables and given/known data

    http://img224.imageshack.us/img224/2459/untitledow9.jpg [Broken]

    2. Relevant equations

    3. The attempt at a solution

    See above picture.

    I'm just curious to see if my method is correct and how exactly would I go about simplifying the answer if indeed it is correct. Thanks to anybody who can help!
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Apr 17, 2007 #2
    Your expression for the derivative of sqrt(xy) using the chain rule is in error. Y is under the square root in the expression, so the first half should be sqrt(y/x)/2. From this you should be able to get the second half.
  4. Apr 17, 2007 #3


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    Rather than writing [itex]\sqrt{xy}[/itex] as (xy)1/2, write it as x1/2y1/2. I think you will find that less confusing.
  5. Apr 17, 2007 #4
    http://img149.imageshack.us/img149/9232/workingdh2.jpg [Broken]

    Thanks for pointing that out, I made the relevant changes, I hope it's a bit better now. The final answer seems very, very long winded though. Am I on the right track? Hope nobody minds me posting the pictures instead, it's easier for me than doing it on the computer!
    Last edited by a moderator: May 2, 2017
  6. Apr 17, 2007 #5
    Yes, you're on the right track now!
  7. Apr 17, 2007 #6
    thanks for speed reply
    My final answer is......

    http://img413.imageshack.us/img413/246/finalanswml7.jpg [Broken]

    amiright? :tongue2:
    Last edited by a moderator: May 2, 2017
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