On Thu, Jun 2, 2011 at 7:10 PM, Renzo Del Fabbro
<renzodelfabbro at alice.it> wrote:
> Raymond Toy <toy.raymond <at> gmail.com> writes:
>
>
>> I didn't check to see if maxima is smart enough to give the expected
>> answer with the division, but it can obviously be done by hand.
>>
>> Ray
>>
>
> yes,of course, but I wanted to know if I could do it by Maxima
> -------------
> But I did not understand the advice of Juan
>
>>
>> ? ? Juan> trigreduce( subst([A=cos(c), B=-sin(c)], A*cos(w*t)+B*sin(w*t)) )
>>
>
> how can I use it ?
>
> Thanks
> Renzo
>
trigreduce is a function. the command I sent you is quite handcrafted.
it does this
1. substitutes A for cos(c) and B for -sin(c). The ouput of subst is
then cos(c)*cos(w*t)-sin(c)*sin(w*t)
2. trigreduce applies trigonometric identities to reduce that
expression, givin cos(w*t+c)
If you have an expression for A and B, solving for c in the equalities
A=cos(c) and B=-sin(c), may not be trivial.
Cheers
--
M. Sc. Juan Pablo Carbajal
-----
PhD Student
University of Z?rich
www.ailab.ch/carbajal