Posted by Anonymous on Thursday, May 6, 2010 at 5:14pm.
Your phrasing does not make sense but I am guessing that you meant the fourth root of 64 or 64^(1/4)
64 = 8*8 = 4*2*4*2 = 4^3 = 2^6
2^6 = 2^4*2^2
so
(2^6)^(1/4) = 2^(4/4)*2^(2/4)
which is 2 sqrt 2
or alternatively
(2^6)^(1/4) =2^(6/4) = 2^(3/2)=sqrt(8) = 2 sqrt2