sqrt.go

package main

import (
  "fmt"
  "math"
)

const delta = 0.001

func Sqrt(x float64) float64 {
	z := float64(1)
	z1 := float64(0)
	for math.Abs(z1 - z) > delta {
		z1 = z
		z = z1 - (z1*z1 - x) / (2*x)
	}
	return z
}

func main() {
	fmt.Println(Sqrt(4))
	fmt.Println(math.Sqrt(4))
}