newton_sqrt.go

package main

import (
	"fmt"
	"math"
)

func Sqrt(x float64) float64 {
	guess := 1.0

	for i := 0; i < 10; i++ {
		guess = guess - ((math.Pow(guess, 2) - x) / (2 * guess))
	}

	return guess
}

func main() {
	x := 2.0

	fmt.Println("real", math.Sqrt(x), "guess", Sqrt(x))
}