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Long Term Support Release

  • Bug fixes for general core bugs in 3.9.x will end* 10 May 2021 (12 months).
  • Bug fixes for security issues in 3.9.x will end* 8 May 2023 (36 months).
  • PHP version: minimum PHP 7.2.0 Note: minimum PHP version has increased since Moodle 3.8. PHP 7.3.x and 7.4.x are supported too.
<?php

/**
 *
 * Function code for the complex acos() function
 *
 * @copyright  Copyright (c) 2013-2018 Mark Baker (https://github.com/MarkBaker/PHPComplex)
 * @license    https://opensource.org/licenses/MIT    MIT
 */
namespace Complex;

/**
 * Returns the inverse cosine of a complex number.
 *
 * @param     Complex|mixed    $complex    Complex number or a numeric value.
 * @return    Complex          The inverse cosine of the complex argument.
 * @throws    Exception        If argument isn't a valid real or complex number.
 */
< function acos($complex)
> function acos($complex): Complex
{ $complex = Complex::validateComplexArgument($complex); $square = clone $complex; $square = multiply($square, $complex); $invsqrt = new Complex(1.0); $invsqrt = subtract($invsqrt, $square); $invsqrt = sqrt($invsqrt); $adjust = new Complex( $complex->getReal() - $invsqrt->getImaginary(), $complex->getImaginary() + $invsqrt->getReal() ); $log = ln($adjust); return new Complex( $log->getImaginary(), -1 * $log->getReal() ); }