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Differences Between: [Versions 39 and 311]

   1  <?php
   2  
   3  /**
   4   *
   5   * Function code for the complex acos() function
   6   *
   7   * @copyright  Copyright (c) 2013-2018 Mark Baker (https://github.com/MarkBaker/PHPComplex)
   8   * @license    https://opensource.org/licenses/MIT    MIT
   9   */
  10  namespace Complex;
  11  
  12  /**
  13   * Returns the inverse cosine of a complex number.
  14   *
  15   * @param     Complex|mixed    $complex    Complex number or a numeric value.
  16   * @return    Complex          The inverse cosine of the complex argument.
  17   * @throws    Exception        If argument isn't a valid real or complex number.
  18   */
  19  function acos($complex)
  20  {
  21      $complex = Complex::validateComplexArgument($complex);
  22  
  23      $square = clone $complex;
  24      $square = multiply($square, $complex);
  25      $invsqrt = new Complex(1.0);
  26      $invsqrt = subtract($invsqrt, $square);
  27      $invsqrt = sqrt($invsqrt);
  28      $adjust = new Complex(
  29          $complex->getReal() - $invsqrt->getImaginary(),
  30          $complex->getImaginary() + $invsqrt->getReal()
  31      );
  32      $log = ln($adjust);
  33  
  34      return new Complex(
  35          $log->getImaginary(),
  36          -1 * $log->getReal()
  37      );
  38  }