(complex) root of unity

[Albert Chan]

Assumed n is positive integer.

Cas> rootsOfOne(n) := e^(2*pi*i*range(n)/n)
Cas> rootsOfOne(3)

[1, 1/2*√3*i-1/2, -1/2*√3*i-1/2]

Cas> rootsOfz(z,n) := z^(1/n) * rootsOfOne(n)
Cas> approx(rootsOfz(3+4i, 3))

[ 1.62893714592 +0.520174502305*i,
−1.26495290636 +1.15061369838*i,
−0.363984239564-1.67078820069*i]

Cas> Ans .^ 3

[3.+4.*i, 3.+4.*i, 3.+4.*i]