exercise-loops-and-functions.go

package main

import (
	"fmt"
	"math"
)

func Sqrt_10(x float64) float64 {
	i := 0
	z := 1.0

	if i < 9 {
		z = z - ((z*z - x) / 2 * z)
	}
	return z
}

func Sqrt(x float64) float64{
	z := 1.0
	var prev_z float64

	for {
		prev_z = z
		z = z - ((z*z - x) / 2 * z)
		if math.Abs(prev_z - z) < 0.0001 {
			return z
		}
	}
}

func main() {
	fmt.Printf("math.Sqrt: %g\n", math.Sqrt(2))
	fmt.Printf("Sqrt_10: %g\n", Sqrt_10(2))
	fmt.Printf("Sqrt: %g\n", Sqrt(2))
}