Re: Simple question about inverse of a function

*To*: mathgroup at smc.vnet.net*Subject*: [mg122529] Re: Simple question about inverse of a function*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Mon, 31 Oct 2011 06:50:24 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201110300922.EAA15359@smc.vnet.net>*Reply-to*: drmajorbob at yahoo.com

f[t_] := (1 - t)^theta Assuming[t >= 0 && t <= 1 && theta >= 1 && theta < Infinity, {Quiet@InverseFunction[f][t]}] {1 - t^(1/theta)} Bobby On Sun, 30 Oct 2011 04:22:58 -0500, Mikael <mikaen.anderson.1969 at gmail.com> wrote: > I have a simple question on how to calculate the inverse of a a > function. This is the function I define: > > f[t_] := (1 - t)^theta > > To calculate the inverse I write: > > Assuming[t >= 0 && t <= 1 && theta >= 1 && theta < Infinity, { > InverseFunction[f[t]]}] > > but the answer I get is > > {InverseFunction[(1 - t)^theta]}. > > Now I know I can do this: > > In[11]:= Solve[f[g[x]]==x,g[x]] > Out[11]= {{g[x]->1-x^(1/theta)}} > > but I wonder what is the correct way of specifying assumptions on t and > theta to make the InverseFunction work. Thanks. > -- DrMajorBob at yahoo.com

**References**:**Simple question about inverse of a function***From:*Mikael <mikaen.anderson.1969@gmail.com>