square root value approximation using newton's method

sqrt_approx.go

package main

import (
	"fmt"
	"math"
)

func Sqrt(x float64) float64 {
	// starting value
	var z float64 = x / 2
	var cnt = 1
	// initial guess
	var prevZ = z
	z -= (z*z - x) / (2 * z)
	fmt.Println("Initial guess: ", z)
	for z <= x {
		cnt++
		prevZ = z
		z -= (z*z - x) / (2 * z)
		fmt.Println("New guess: ", z)
		diff := prevZ - z
		// tolerance between new and previous guess
		if diff < 0.0000001 { // acceptable error between guesses
			fmt.Println("Count: ", cnt)
			return z
		}
	}
	return 0
}

func main() {
	var x float64 = 12334
	fmt.Println("Guess: ", Sqrt(x))
	fmt.Println("Answer: ", math.Sqrt(x))
}