Newton's method for sqrt()

main.go

package main

import "fmt"

func main() {

	i := 1

	var sqr, x, cm float64
	sqr = 16
	x = 1

	for i != 0 {
		cm = ((x*x - sqr) / (x * sqr))
		x = x - cm
		if cm < 1e-7 && -cm < 1e-7 {
			i = 0
		}
	}
	fmt.Println(x)
}