document.write( "Question 250791: The volume, V, of a sphere is a function of its radius, r, where V = 4/3pir^3. Express the volume as a function of the diameter, d.\r
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Algebra.Com's Answer #184585 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
formula in terms of radius is:\r
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\n" ); document.write( "\n" ); document.write( "v = (4/3) * pi * r^3\r
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\n" ); document.write( "\n" ); document.write( "radius equals diameter divided by 2:\r
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\n" ); document.write( "\n" ); document.write( "r = d/2\r
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\n" ); document.write( "\n" ); document.write( "replace r with (d/2) to get:\r
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\n" ); document.write( "\n" ); document.write( "v = (4/3) * pi * (d/2)^3\r
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\n" ); document.write( "\n" ); document.write( "(d/2)^3 is the same as (1/2)^3 * d^3 so your equation becomes:\r
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\n" ); document.write( "\n" ); document.write( "v = (4/3) * pi * (1/2)^3 * d^3 which becomes:\r
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\n" ); document.write( "\n" ); document.write( "v = (4/3) * pi * (1/8) * d^3\r
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\n" ); document.write( "\n" ); document.write( "simplify to get:\r
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\n" ); document.write( "\n" ); document.write( "v = (1/6) * pi * d^3\r
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\n" ); document.write( "\n" ); document.write( "example:\r
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\n" ); document.write( "\n" ); document.write( "let d = 16\r
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\n" ); document.write( "\n" ); document.write( "that makes r = 8\r
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\n" ); document.write( "\n" ); document.write( "v = (4/3) * pi * r^3 = (4/3) * pi * (8)^3 = (4/3) * pi * 512 = 682.67 * pi\r
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\n" ); document.write( "\n" ); document.write( "v = (1/6) * pi * d^3 = (1/6) * pi * 16^3 = (1/6) * pi * 4096 = 682.67 * pi\r
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\n" ); document.write( "\n" ); document.write( "both forms are equivalent, so the formula in terms of d is:\r
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\n" ); document.write( "\n" ); document.write( "v = (1/6) * pi * d^3\r
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