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Math Help - rearranging

  1. #1
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    rearranging

    Hi, could anyone please help me with this formula;

    V=1/3 pie r^2h i need to make r the subject i di v-1/3=pier^2h
    v-1/3-pie=r^2h
    v-1/2-pie-h=r^2 then divide by 2 but i dont think thats realy going to be right and i tried a few others but im gtin into a muddle thnx for any help x
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  2. #2
    Bar0n janvdl's Avatar
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    Quote Originally Posted by Chez_ View Post
    Hi, could anyone please help me with this formula;

    V=1/3 pie r^2h i need to make r the subject i di v-1/3=pier^2h
    v-1/3-pie=r^2h
    v-1/2-pie-h=r^2 then divide by 2 but i dont think thats realy going to be right and i tried a few others but im gtin into a muddle thnx for any help x
    V = \frac{1}{3} \pi r^2 h

    3 V = \pi r^2 h

    \frac{3 V}{\pi h} = r^2

    r = \sqrt{ \frac{3 V}{\pi h} }
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  3. #3
    MHF Contributor kalagota's Avatar
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    Taguig City, Philippines
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    Quote Originally Posted by Chez_ View Post
    Hi, could anyone please help me with this formula;

    V=1/3 pie r^2h i need to make r the subject i di v-1/3=pier^2h
    v-1/3-pie=r^2h
    v-1/2-pie-h=r^2 then divide by 2 but i dont think thats realy going to be right and i tried a few others but im gtin into a muddle thnx for any help x
    awww.. first of all, it is PI and not pie..

    so, i recognize it as the formula of the volume of a cone.

    V = \frac{1}{3} \pi r^2h and you want to solve for r in terms of the others, is that it?

    so, multiply 3 to both sides, then you will have 3V = 3\cdot \frac{1}{3}\pi r^2 h = \pi r^2 h.. multiply \frac{1}{\pi h}, so that r^2 remains of the right side.. that is \frac{3V}{\pi h} = r^2.. lastly, take the squareroot of both side, this will become, \sqrt{\frac{3V}{\pi h}} = r.. then you are done..
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