N-th roots of complex numbers?



On Mon, Sep 30, 2013 at 10:08 PM, Alasdair McAndrew <amca01 at gmail.com> wrote:

> I think Maxima needs some help here.  When I enter
>
> solve(z^3 = 8*%i,z);
>
> I obtain an empty list as the solution.

Dunno what's going on. With Maxima 5.31.1 + Clisp + Linux, I get:

(%i2) solve(z^3 = 8*%i,z);
(%o2) [z = (-1)^(1/6)*sqrt(3)*%i-(-1)^(1/6),
       z = -(-1)^(1/6)*sqrt(3)*%i-(-1)^(1/6),z = 2*(-1)^(1/6)]
(%i3) rectform(%);
(%o3) [z = %i-sqrt(3),z = -2*%i,z = %i+sqrt(3)]

best

Robert Dodier