pw.mac version 2.3.1
- Subject: pw.mac version 2.3.1
- From: Alexey Beshenov
- Date: Sat, 20 Dec 2008 16:13:42 +0300
On Saturday 20 December 2008 15:54:15 Barton Willis wrote:
> What's the story? The equation x^3-23*x^2-71*x-11 = 0 has three
> real roots, but the roots expressed in terms of radicals involves
> %i. So Maxima wrongly assumes that these solutions are nonreal.
trigsimp & rectform do the trick.
(%i1) s : map('rhs, solve(x^3-23*x^2-71*x-11))$
(%i2) map ('imagpart, s);
(%o2) ...
(%i3) map (lambda([e], is(imagpart(e)=0)), s);
(%o3) [false,false,false]
(%i4) map (lambda([e], is(equal(imagpart(e),0))), s);
(%o4) [true,true,true]
(%i5) map (lambda([e], freeof(%i,e)), s);
(%o5) [false,false,false]
(%i6) map (lambda([e], freeof(%i, trigsimp(rectform(e)))), s);
(%o6) [true,true,true]
--
Prickle Prickle, Aftermath 62 YOLD 3174
Alexey Beshenov http://beshenov.ru/