Re: Sinh, Cosh and all that

*To*: mathgroup at smc.vnet.net*Subject*: [mg2238] Re: Sinh, Cosh and all that*From*: "Brian J. Albright" <albright at physics.ucla.edu>*Date*: Wed, 18 Oct 1995 01:53:56 -0400*Organization*: UCLA Department of Physics and Astronomy

Kenny Breuer <breuer at mit.edu> wrote: >I'm looking for a set of transformation rules that will convert >expoentials to hyperbolic functions (analagous to the function >ComplexToTrig in the Trigonometry package) > >For example: >In: ConvertToHyp[ Exp[3x] + Exp[-3x] ] > >Out: 2 Cosh[3x] > >Thanks > >Kenny Breuer >breuer@mit > Hi. Perhaps you might try In[1]:= ExpToHyp[x_] := x //. Exp[a_] -> (Cosh[a] + Sinh[a]) e.g. In[2]:= ExpToHyp[ Exp[s] - Exp[-s] + Exp[3 x] + Exp[-3 x] ] Out[2]:= 2 Cosh[3 x] + 2 Sinh[s] -Brian -- Brian J. Albright | Department of Physics and Astronomy, UCLA | To err is human... albright at physics.ucla.edu | to err really big http://bohm.physics.ucla.edu/~albright | is government.