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    (Original post by hihihihi)
    Find the volume when the following shaded region is rotated 360 degrees about the y-axis.


    AAAAAAAAAAAAAAAAAAAAAH!

    Y axis!? I am such a buffoon.. i've been trying for half an hour and I read the bloody question wrong.


    poo.
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    (Original post by kimoni)
    AAAAAAAAAAAAAAAAAAAAAH!

    Y axis!? I am such a buffoon.. i've been trying for half an hour and I read the bloody question wrong.


    poo.
    yeah that's why mik1a's method doesn't work i think. you must integrate x^2 with respect to y and not the other way.
    y= x²
    => x=√y
    Vol. = Pi * ∫ (x²)dy
    = pi * ∫ y dy
    =pi*[ y²/2] between 1 and 0
    etc.

    y=2-x²
    => x=√(2-y)
    Vol. = Pi * ∫ (x²)dy
    = pi * ∫ (2-y) dy
    = pi * [2y - y²/2] between 2 and 1.
    etc.
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    pheeeeew.
    done it.


    now to move on to something else!!
 
 
 
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Updated: June 20, 2004
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