square-root.go

package main

import (
	"fmt"
)

func Sqrt(x float64) float64 {
	guess := 1.0
	var lastGuess float64
	var lastTwoGuess float64
	const MaxIterCount = 10
	for i := 0; i < MaxIterCount; i++ {
		fmt.Printf("Iteration %d: z = %v\n", i, guess)
		lastTwoGuess = lastGuess
		lastGuess = guess
		guess -= (guess * guess - x)/(2 * guess)
		if guess == lastGuess && lastGuess == lastTwoGuess {
			// we are already at the square root
			fmt.Println("definitive sqrt found")
			break
		}
	}
	
	return guess
}

func main() {
	fmt.Println(Sqrt(5))
}