MaplePrimes - answers and comments on Question, symbolic roots of 8th order polynomial

Lengthy

Robert Israel — Wed, 08 Jul 2009 18:42:17 Z

I don't know why this is unexpected. Your polynomial is a quartic in z = Z^2 with general coefficients except for no linear term (i.e. you could get any quartic c4*z^4 +c3*z^3+c2*z^2+c0 by appropriate choice of A,B,C,D,L). A suitable translation z -> z - k will give you a completely general quartic. The formula for the solution of the general quartic in radicals is extremely complicated.

In maple?

engrrizwan — Wed, 08 Jul 2009 19:57:53 Z

Many thanks....

if i try finding Rootof (c4*z^4 +c3*z^3+c2*z^2+c0) ; allvalues(%) ; maple does not compute and displays Rootof(c4*z^4 +c3*z^3+c2*z^2+c0). how can i make a translation z -> z - k .

it works

engrrizwan — Thu, 09 Jul 2009 00:08:27 Z

thanks a lot.... it works :)

regards

RootOf

Robert Israel — Wed, 08 Jul 2009 21:02:51 Z

You want RootOf, not Rootof. Also, you need to tell it the variable, z.