blob: 296138f0f52d7756ce4b97c2874b2608e24c4e39 [file] [log] [blame]
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build ignore
package main
import (
"fmt"
"math"
)
const delta = 1e-6
func Sqrt(x float64) float64 {
z := x
n := 0.0
for math.Abs(n-z) > delta {
n, z = z, z-(z*z-x)/(2*z)
}
return z
}
func main() {
const x = 2
mine, theirs := Sqrt(x), math.Sqrt(x)
fmt.Println(mine, theirs, mine-theirs)
}