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Can anyone answer this question

  1. Dec 27, 2009 #1
    Draw a rectangle , start quadrant having one leg on the Axis -Y and other on the Axix -X and vertex on the curve
    y=1-0.61x^2

    You need to find the co-ordinates of the rectangle and find out which form of rectangle has got more area.
     
  2. jcsd
  3. Dec 27, 2009 #2

    tiny-tim

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    Hi jtesttubes! :wink:

    Show us what you've tried, and where you're stuck, and then we'll know how to help! :smile:
     
  4. Dec 27, 2009 #3

    HallsofIvy

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    Yes, I can answer that. Thank you for asking.
     
  5. Dec 28, 2009 #4
    I have worked out a calculation, but i just want to confirm with you whether this is the way to work out this question, i got the co-ordinates of the rectangle. Is it correct

    Area = x*y - basic formula for area.
    A=x(1-0.61x^2)
    A=x-0.61x^3
    dA/dx = 1-1.83x^2
    0=1-1.83x^2
    x=sqrt(1/1.83)
    x=0.739
    y=1-0.61(0.739)^2
    y=0.66667
    coordinates are (0.739,0.6667)
     
  6. Dec 28, 2009 #5

    tiny-tim

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    Hi jtesttubes! :smile:

    (try using the X2 tag just above the Reply box :wink:)
    yes, that looks fine. :smile:

    (except you could have got y more quickly by noting that 0.61x2 is 1/3 of 1.83x2, and you know exactly what that is :wink:)
     
  7. Dec 29, 2009 #6
    Oh thanks i have some doubts on my workings now im happy that it is the right way to work out, yes sometimes i do not follow shortcuts on working out this kind of equations.
     
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