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Math Help - Question about derivative function

  1. #1
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    Question Question about derivative function

    Hello everyone,

    I have a function for which I must first find the derivative implcite.
    x ^ 3 + y ^ 3 = 6XY, nothing fancy so far:



    However, just after i been asked to calculate y'(0)?

    I think so, y'(0) = 2/y ! I stuck there because it seems I need a number. So without a variable. Any an idea?

    thank you
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  2. #2
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    have a look at the graph of the relation ...
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  3. #3
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    Thanks for your reply, but what can i conclude?

    regards
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  4. #4
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    Of course, from the original equation, when x= 0, y= 0 also. That's why you cannot use your formula- you get 0/0. And, as skeeter's graph shows, there are two distinct derivatives at x= 0, one 0 and the other infinite.
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  5. #5
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    So basicly what you are saying is y'(0) = 0 right? and the other infinite?!
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  6. #6
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    Wouldn,t it be better if i try i just try to calculte in a point A (0,0) like on the graph and just give the infinite answer?
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