Re: Expanding Trig Power Identities

*To*: mathgroup at smc.vnet.net*Subject*: [mg30357] Re: [mg30348] Expanding Trig Power Identities*From*: Andrzej Kozlowski <andrzej at tuins.ac.jp>*Date*: Sun, 12 Aug 2001 02:29:47 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

For example: In[78]:= TrigReduce[ Cos[a](Cos[b])^3] Out[78]= 1 - (Cos[a - 3 b] + 3 Cos[a - b] + 3 Cos[a + b] + Cos[a + 3 b]) 8 Andrzej Kozlowski Toyama International University JAPAN http://platon.c.u-tokyo.ac.jp/andrzej/ On Saturday, August 11, 2001, at 04:40 PM, atjurhs wrote: > How can I use Mathematica to find the expansion of various > trigonometric power > identities? I've already tried TrigExpand w/o succes. > > I have functions of the form Sin[a](Sin[b])^n and Cos[a](Cos[b])^n > where n is a power. > > I would like to get the fully expanded version of these functions, so > that there are no more powers involved. If n=1 then the answer is > just the standard product relations that you can look up in the back > of any trig book. But I need to be able to do it for higher powers of > n. And I don't know how to even do it for n=1. > >