Go code using Newton's method to find the Square Root of an integer

sqrt.go

package main

import (
	"fmt"
	"math"
)

const (
	TOLERANCE=0.00001
)

func Sqrt(x float64) float64 {
	var z float64 = 1

	for i:=0; i < 10; i++ {
		y := z
		if z -= (z*z - x) / (2*z); math.Abs(y-z) < TOLERANCE {
			break
		}
	}
	return z
}

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