A Tour of Go 23: Exercise: Loops and Functions

gistfile1.go

package main

import (
	"fmt"
	"math"
)

// square root function using Newton's method
func Sqrt(x float64) float64 {
	z := 1.0
	for math.Abs(z*z-x) > 1e-10 {
		z = z - (z*z-x)/(2*z)
	}
	return z
}

func main() {
	fmt.Println(Sqrt(2))
	fmt.Println(math.Sqrt(2))
}