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URGENT is this correct? MATHS INTEGRATION watch

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    The gradient of the curve is given by dy/dx= (x^2+3)^2 divided by x^2, x is not 0
    (A) Show that day/dx = x^2+6+9x^-2
    My answer is : proven
    The point. (3,20) lies on C
    (B) find an equation for the curve C in the form y=f(x)
    I have got:
    X^2 divided by 2/3 +3/2(x^2)
    Y=(x^2+6+9x^-2) +c
    20= 3(x^2+6+9x^-2) +c
    20= 3x^2 +18 +27x^-2 +c
    3x^2+27x^-2-2+c
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    I got: Attachment 723630
    (Ignore the other image that was before I saw you have a coordinate)
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    (Original post by RantingWhovian)
    I got: Attachment 723630
    The last term is incorrect. You need to divide the 9x^(-2) by the -2, not by -1.
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    (Original post by VannR)
    The last term is incorrect. You need to divide the 9x^(-2) by the -2, not by -1.
    I don’t use a method, I just do it in my head. Surely if you differentiate -9x^-1 you get 9x^-2, so that would work??
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    (Original post by RantingWhovian)
    I don’t use a method, I just do it in my head. Surely if you differentiate -9x^-1 you get 9x^-2, so that would work??
    Hahaha yeah, you're right, the method is that you divide by the exponent plus 1.....which is -1 in this case! Please forgive, I'm a second-year mathematics student who has not integrated a simple polynomial in months
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    (Original post by RantingWhovian)
    I got: Attachment 723630
    (Ignore the other image that was before I saw you have a coordinate)
    + c needed
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    (Original post by Muttley79)
    + c needed
    I said ignore this one
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    (Original post by VannR)
    Hahaha yeah, you're right, the method is that you divide by the exponent plus 1.....which is -1 in this case! Please forgive, I'm a second-year mathematics student who has not integrated a simple polynomial in months
    I’ve never been taught it before 😄
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    (Original post by RantingWhovian)
    I said ignore this one
    So why did you leave it there? Just delete the post!
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    (Original post by Muttley79)
    So why did you leave it there? Just delete the post!
    I tried to! I’m not stupid. I had originally put it then saw the other part of OP’s post and changed my answer. I thought I’d deleted the other attachment but saw it and added the bracket. The app won’t let me delete the post
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Updated: February 8, 2018
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