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    hey!
    i seem to be stuck on this question:
    http://www.mei.org.uk/files/papers/c408ju_op58.pdf
    (paper A, question 5)
    I've gotten part a) which is 3u
    but im completely stuck on part b)
    i have a test tomorrow so would be really grateful!
    thanks
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    Use your x or y value to substitute and rearrange to find the value of u at that point

    Edit: use both x and y values. Using the x value only will give two possible values of u, you need the y to confirm which is right :yes:
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    (Original post by Serine Soul)
    Use your x or y value to substitute and rearrange to find the value of u at that point

    Edit: use both x and y values. Using the x value only will give two possible values of u, you need the y to confirm which is right :yes:
    i dont really understand sorry could you show me please? xx
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    (Original post by xoharrypotter)
    i dont really understand sorry could you show me please? xx
    Right, so you're given the coordinates of the point to be (5,16) so x=5 and y=16 at this point

    The first parametric equation states that
    x= 1 + u^2

    If I sub in x= 5, I can rearrange 5 = 1 + u^2 to find that u is either 2 or -2

    u can be either value so we use the equation involving y, setting 16 = 2u^3. From rearranging this, we find that u can only be positive 2 (cube root of a positve number is always positive)

    Does that make a bit of sense?
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    (Original post by Serine Soul)
    Right, so you're given the coordinates of the point to be (5,16) so x=5 and y=16 at this point

    The first parametric equation states that
    x= 1 + u^2

    If I sub in x= 5, I can rearrange 5 = 1 + u^2 to find that u is either 2 or -2

    u can be either value so we use the equation involving y, setting 16 = 2u^3. From rearranging this, we find that u can only be positive 2 (cube root of a positve number is always positive)

    Does that make a bit of sense?
    yes thank you so much!
    thats really helped a lot
    sorry im a bit clueless sometimes
    thank you again xx
 
 
 
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