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Differentiation of implicit functions Watch

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    where did I screw up?Attachment 691242691244Attachment 691242691244691200
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    -- wrong working out --
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    It seems OK until you try to simplify the fractions
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    You're nearly there; you're correct up until the third from the last line, where you've dropped a plus sign in the denominator. You then simply need to multiply the top and bottom by x^2 y^2.
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    (Original post by ckfeister)
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    Remember, when multiplying out a fraction on both the top and bottom, it involves multiplying every term.

    The fraction 2y+2/x^2 / -2x+3/y^2 is correct (though you can write the bottom as 3/y^2- 2x)

    The working out beyond that is wrong. First, try multiplying EVERY term by x^2 to get rid off the fraction in the numerator, and do the same for the y^2 in the denominator.
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    (Original post by MoniC255)
    Remember, when multiplying out a fraction on both the top and bottom, it involves multiplying every term.

    The fraction 2y+2/x^2 / -2x+3/y^2 is correct (though you can write the bottom as 3/y^2- 2x)

    The working out beyond that is wrong. First, try multiplying EVERY term by x^2 to get rid off the fraction in the numerator, and do the same for the y^2 in the denominator.
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    Ok, I got this, where did I mess up now?
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    (Original post by Gregorius)
    You're nearly there; you're correct up until the third from the last line, where you've dropped a plus sign in the denominator. You then simply need to multiply the top and bottom by x^2 y^2.
    Above post.
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    (Original post by ckfeister)
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    Ok, I got this, where did I mess up now?
    You need to multiply top AND bottom by both x^2 and y^2.
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    (Original post by ckfeister)
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    Ok, I got this, where did I mess up now?
    You only multiplied the terms in the numerator by x^2. Multiply EVERY term. Take it slow and you'll get it. Multiply the 2y, -2x and 3/y^2 by x^2. Then do the same for the y^2.
 
 
 
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