Re: Inverse of function

*To*: mathgroup at smc.vnet.net*Subject*: [mg121420] Re: Inverse of function*From*: "Oleksandr Rasputinov" <oleksandr_rasputinov at hmamail.com>*Date*: Wed, 14 Sep 2011 05:16:07 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <j4neqn$54e$1@smc.vnet.net>

On Tue, 13 Sep 2011 12:29:27 +0100, Berthold Hamburger <b-hamburger at artinso.com> wrote: > Hi, > > I stumbled over a small riddle using mathematica 8. Asking for the > inverse of the function f(x)= x^2, I receive the solution: f^(-1)(x) > = =C2=B1sqrt(x) > > Why is that so? I had rather expected an error message. > > Regards > Perhaps this is a result of the particular way in which you asked, or some assumptions inadvertently applied? In a new session, InverseFunction behaves as expected: In[1] := InverseFunction[#^2 &] During evaluation of In[1] := InverseFunction::ifun: Inverse functions are being used. Values may be lost for multivalued inverses. Out[1] = -Sqrt[#1] &