acos.php

Go to the documentation of this file.

<?php

namespace Complex;

if (!function_exists(__NAMESPACE__ . '\\acos')) {
    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()
        );
    }
}