Re: Help with Identities

*To*: mathgroup at smc.vnet.net*Subject*: [mg65599] Re: [mg65585] Help with Identities*From*: "David Park" <djmp at earthlink.net>*Date*: Mon, 10 Apr 2006 02:31:19 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Sven, Is this what you mean? Simplify[Log[x/y] == Log[x] - Log[y], x > 0 && y > 0] True Mathematica doesn't say the unsimplified expression is False. It simply leaves it unchanged. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Sven C. Koehler [mailto:schween at snafu.de] To: mathgroup at smc.vnet.net Hello! As an occasional mathematican, I sometimes forget that i.e. Log[x/y] is very similar to Log[x] / Log[y] Is there some way in Mathematica to see how an mathematical expression could look like alternatively? (Something like the opposite of Simplify.) And then I wonder why Log[x/y] === Log[x] - Log[y] is False. Can I instruct Mathematica to explain why this is False? Best wishes, Sven