Radical Expressions

The volume of a sphere is 4pi(r)/3, so the denominator is already rational.

To find r, just use the normal algebraic properties (Addition POE, Subtraction, etc.)

The volume of a sphere of radius "r" is V=4/3pi r cubed. How do i find r and rationalize the denominator?

V=4/3pi r cubed
V=4pi/3 *r cubed

multiply BOTH sides by 3/(4pi) and you get

3V/(4pi) = r cubed

r = [ 3V/(4pi) ] ^(1/3)

I don't believe that you can rationalize the denominor, pi to the power of something will always be on the bottom and pi is an irrational number.