cbrt.go

package main

import "fmt"
import "math/cmplx"

const d float64 = 0.0001

func Cbrt(x complex128) complex128 {
  z0, z := complex128(0), complex128(1)
	for cmplx.Abs(z - z0) > d {
		z0, z = z, z - (z*z*z - x)/(3*z*z)
	}
	return z
		
}

func main() {
	fmt.Println(Cbrt(2))
}