Re: Inverse function warnings

*To*: mathgroup at smc.vnet.net*Subject*: [mg99238] Re: Inverse function warnings*From*: dh <dh at metrohm.com>*Date*: Thu, 30 Apr 2009 06:25:34 -0400 (EDT)*References*: <gt90og$l55$1@smc.vnet.net>

Hi, your equation is a transcendental equation with infinitely many solutions. Reduce gets them all. You get them by setting C[1] to some arbitrary integer. You may eliminate the warning by: Quiet@Solve[3^(2 x) - 12 (3^x) + 27 == 0, x] Daniel davef wrote: > 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 >