Exercise: Loops and Functions.go

package main

import (
	"fmt"
)

func Sqrt1(x float64) float64 {
	//z := 1.0
	z := float64(1)
	for i := 0; i < 10; i++ {
		z -= (z*z - x) / (2 * z)
	}
	return z
}

func abs(x float64) float64 {
	if x < 0 {
		return x * -1
	} else {
		return x
	}
}

func Sqrt(x float64) float64 {
	//z := 1.0
	z := float64(1)
	tmp := x
	for {
		//tmp := z
		z -= (z*z - x) / (2 * z)
		if abs(tmp-z) < 0.00000005 {
			break
		}
		tmp = z
	}
	return z
}

func main() {
	fmt.Println(Sqrt(16.0))
}