~~~ package main import ( "fmt" "math" ) func Sqrt(x float64) float64 { z := float64(1) tmp := float64(0) for math.Abs(tmp - z) > 0.0000000001 { tmp = z z = (z + x/z)/2 } return z } func main() { fmt.Println(Sqrt(2)) fmt.Println(math.Sqrt(2)) } ~~~