Re: TrigExpand - Odd behavior
- To: mathgroup at smc.vnet.net
- Subject: [mg55428] Re: TrigExpand - Odd behavior
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Wed, 23 Mar 2005 05:34:39 -0500 (EST)
- References: <200503220851.DAA23768@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
On 22 Mar 2005, at 09:51, Bob Stagat wrote: > > Try executing the following three lines and explain the last result... > > Cos[45 Degree] > > Cos[x+45 Degree] > > Cos[x+45 Degree]//TrigExpand > > Thanks... > ~ BS ~ > > There is nothing wrong and nothing to explain. What you get is the expansion of iof Cos[x+45 Degree] in terms of Sin[x], Cos[x], Sin[1 Degree], Cos[1 Degree]. What else did you expect? You can see that the answer is correct by substituting a numerical value for x as follows: Chop[(Cos[x+45 Degree]//TrigExpand)/.x->45 Degree//N] 0 Chop[(Cos[x+45 Degree]//TrigExpand)/.x->15 Degree//N] 0.5 which is as it should be. Andrzej Kozlowski
- References:
- TrigExpand - Odd behavior
- From: "Bob Stagat" <stagat@linkline.com>
- TrigExpand - Odd behavior