Re: usage of TrigToExp?
- To: mathgroup at smc.vnet.net
- Subject: [mg95476] Re: [mg95431] usage of TrigToExp?
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Mon, 19 Jan 2009 03:00:52 -0500 (EST)
- Reply-to: hanlonr at cox.net
Start from a fresh kernel. TrigToExp[Cos[2 x]] 1/2/E^(2*I*x) + (1/2)*E^(2*I*x) % // FullSimplify Cos[2*x] %% // ExpToTrig Cos[2*x] TrigToExp[Cos[y] Sin[x]] (1/4)*I*(E^((-I)*x) - E^(I*x))* (E^((-I)*y) + E^(I*y)) % // FullSimplify Sin[x]*Cos[y] %% // ExpToTrig Sin[x]*Cos[y] Perhaps you have something in $Post or have an older version and have executed the package Miscellaneous`RealOnly` Bob Hanlon ---- zatuch <zatuch at gmail.com> wrote: ============= Hello, Results from function TrigToExp seemed weird to me. Could anyone please give me a good explanation on its usage. Thanks a lot. In[41]:= TrigToExp[Cos[2 x]] During evaluation of In[41]:= Nonreal::warning: Nonreal number encountered. Out[41]= Nonreal In[43]:= TrigToExp[Cos[y] Sin[x]] Out[43]= 0 Zatuch -- Bob Hanlon