Go tour "Cbrt" method: http://tour.golang.org

Complex Cube Roots Exercise

package main

import (
    "fmt"
    "math/cmplx"
)

func Cbrt(x complex128) complex128 {
    result := complex128(x)
    for i := 0; i < 100; i++ { // To ensure high precision
        result = result - ((cmplx.Pow(result, 3) - x)/(3 * cmplx.Pow(result, 2)))
    }
    return result
}

func main() {
    fmt.Println("Actual   :" , cmplx.Pow(9, 1.0/3.0))
    fmt.Println("Estimate :", Cbrt(9))
}