exact integer from Log[ ]

*To*: mathgroup at smc.vnet.net*Subject*: [mg58321] exact integer from Log[ ]*From*: "Trevor Baca" <trevorbaca at gmail.com>*Date*: Tue, 28 Jun 2005 05:13:22 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

The question is how to get the exact integer 13 when we let f = 880*2^(1/12) and let expr = Log[2^(1/12), f/440] with no numerics (only exact integers) in both expressions. It seems that expr should already equal the integer 13 exactly, yet evaluating expr gives (12*Log[2*2^(1/12)])/Log[2] or Log[8192]/Log[2] with Simplify[expr], which, while clearly 13 to the eye, still isn't exactgly 13 on the page. So how do you get 13 back out of expr, preferably without recourse to numerics? Trevor.