Newton approx

newton.go

package main

import (
	"fmt"
	"math"
)

func Sqrt(x float64) float64 {
	delta, z := float64(1), float64(1)
	for delta > 1e-9 {
		prev := z
		z = z - (math.Pow(z, 2) - x) / (2 * z)
		delta = math.Abs(z - prev)
	}
	fmt.Println(math.Sqrt(x))
	return z
}

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