Inverse function warnings

*To*: mathgroup at smc.vnet.net*Subject*: [mg99164] Inverse function warnings*From*: davef <davidfrick2003 at yahoo.com>*Date*: Wed, 29 Apr 2009 03:48:44 -0400 (EDT)

When I execute this in Mathematica 7: Solve[3^(2 x) - 12 (3^x) + 27 == 0, x] I get this: Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found; use Reduce for complete solution information. >> {{x->1},{x->2}} 1 amd 2 are proper solutions but is it possible to avoid the warning? If I use Reduce: Reduce[3^(2 x) - 12 (3^x) + 27 == 0, x] I get a set of 1 and 2 added to some imaginary number terms that I don't quite understand. I guess my question is: why would the use of inverse functions be so unreliable a solution as to necessitate a warning? And in the interest of clean output, can the warning be supressed other than by deleteing the cell? Thanks