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    Find the value of dy/dx at the point (1,1) where 4xy^2 + 6x^2/y = 10

    I HONESTLY REALLY DONT UNDERSTAND THIS C4 DIFFERENTIATION PLEASE HELP SOMEONE. THANK-YOU XX
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    you've got differentiate implicitly
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    (Original post by Robofish)
    you've got differentiate implicitly
    Yeah i know you have to do that, but i dont really get it .
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    Use the product rule to differentiate (with respect to x) 4xy^2, then the quotient rule to differentiate(again wr.t. x) (6x^2)/y. The sum of these two derivatives will equal the derivative of 10 (ie 0).

    Remember that \frac{d}{dx}(y)=\frac{dy}{dx}
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    (Original post by namedeprived)
    Use the product rule to differentiate (with respect to x) 4xy^2, then the quotient rule to differentiate(again wr.t. x) (6x^2)/y. The sum of these two derivatives will equal the derivative of 10 (ie 0).

    Remember that \frac{d}{dx}(y)=\frac{dy}{dx}
    i dont know when you have to write dy/dx after you differentite it using the product and quotient rule
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    (Original post by klgyal)
    i dont know when you have to write dy/dx after you differentite it using the product and quotient rule
    4xy^2 is a product of 4x and y^2. The derivative of 4x (wrt x) is 4. Now let u=y^2

    du/dy = 2y

    Using the chain rule,

    (du/dx)=(du/dy)(dy/dx) = (2y)(dy/dx)

    So the derivative of y^2 (wrt x) is (2y)(dy/dx). So by the product rule, the derivative of 4xy^2 (wrt x) is 8xy(dy/dx) + 4y^2

    Do you understand now?
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    thanks i get it now
 
 
 
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