acos

    (PHP 4, PHP 5, PHP 7, PHP 8)

    acos — Arc cosine

    Опис

    acos(float $num): float

    Returns the arc cosine of num in radians. acos() is the inverse function of cos(), which means that $num == cos(acos($num)) for every value of num that is in the domain of acos().

    Параметри

    num

    The argument to process

    Значення, що повертаються

    The arc cosine of num in radians.

    Прогляньте також

    Found A Problem?

    Learn How To Improve This Page • Submit a Pull Request • Report a Bug
    ＋add a note

    User Contributed Notes 1 note

    up
    0
    isweet479338 at gmail dot com
    16 days ago
    Parameter:
    $num: A float value between -1 and 1. (Outside this range will return NAN)

    Returns:
    The arc cosine of the number in radians.

    NAN (Not A Number) if the input is outside [-1, 1].

    <?php
    $cosValue     = 0.5;
    $angle = acos($cosValue); // returns angle in radians
    echo $angle; // 1.0471975512 (which is ~60 degrees)

    echo rad2deg($angle); // Convert to degrees: ~60
    ?>
    ＋add a note
    To Top