trigexpand
2011/4/28 Jos? Carlos Santos <jcsantos at fc.up.pt>
> Hi all,
>
> If I ask Maxima to compute cos(2*acos(.8)) or cos(3*acos(-.5)), I get the
> right answers. However, Maxima seems unable to simplify the expressions
> cos(2*acos(x)) or cos(3*acos(x)), even if I use the trigsimp command. I
> would like to declare that _x_ belongs to [-1,1], to see if that solves the
> problem. Is it possible? If not, is there some way of making Maxima "see"
> that
>
> cos(3*acos(x)) = 4x^3 - 3x?
>
> Best regards,
>
> Jose Carlos Santos
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima
>