Exercise: Loops and Functions in go tour

go_for_ex

package main

import (
	"fmt"
	"math"
)

const MAX_DELTA = 0.01

func isEnough(d float64) bool {
	if d < 0 {
		d = -d
	}	
	return d < MAX_DELTA
}

func Sqrt(x float64, z float64) float64 {
    var tmp float64
	for {
		tmp = z - (z * z - x) / 2 * z
	 	
		if d := tmp - z; isEnough(d) {
		    return tmp
		}
		
		z = tmp
	} 
}

func main() {
	fmt.Println(Sqrt(9, 1))
	fmt.Println(math.Sqrt(9))
}