z, prev_z := x, x+1

eps := math.Pow(10, -10)

for float64(cmplx.Abs(z - prev_z)) - eps > 0 {

prev_z = z

z = z - (cmplx.Pow(z, 3) - x)/(3*cmplx.Pow(z, 3))

}

return z

var x complex128 = 2

fmt.Println(MyCbrt(x))

fmt.Println(cmplx.Pow(x, 1.0/3))