index.js

/**
* @license Apache-2.0
*
* Copyright (c) 2026 The Stdlib Authors.
*
* 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.
*/

'use strict';

var pow = require( '@stdlib/math/base/special/pow' );
var sin = require( '@stdlib/math/base/special/sin' );
var brentq = require( './../lib' );

function f( x ) {
	return pow( x, 3 ) - ( 2.0 * x ) - 5.0;
}

var root = brentq( f, 2.0, 3.0 );
console.log( 'f(x) = x^3 - 2x - 5' );
console.log( 'Root: %d', root );
console.log( 'f(root): %d', f( root ) );

// Example with options
function g( x ) {
	return sin( x );
}

root = brentq( g, 3.0, 4.0, {
	'xtol': 1e-4
});
console.log( '\nf(x) = sin(x)' );
console.log( 'Root matching 3.14 on [3, 4] with xtol 1e-4: %d', root );
console.log( 'f(root): %d', g( root ) );