sqrt_newton_raphson.go

// Copyright 2018 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package sqrt

func sqrtNewton(n int64) float64 {
	x := float64(n)
	z := x / 2
	diff := 1.0
	for abs(diff) > precision {
		diff = (z*z - x) / (2 * z)
		z -= diff
	}
	return z
}