Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Statistical.php
public static function BETADIST($value, $alpha, $beta, $rMin = 0, $rMax = 1)
    {
        $value = Functions::flattenSingleValue($value);
        $alpha = Functions::flattenSingleValue($alpha);
        $beta = Functions::flattenSingleValue($beta);
        $rMin = Functions::flattenSingleValue($rMin);
        $rMax = Functions::flattenSingleValue($rMax);

        if ((is_numeric($value)) && (is_numeric($alpha)) && (is_numeric($beta)) && (is_numeric($rMin)) && (is_numeric($rMax))) {
            if (($value < $rMin) || ($value > $rMax) || ($alpha <= 0) || ($beta <= 0) || ($rMin == $rMax)) {
                return Functions::NAN();
            }
            if ($rMin > $rMax) {
                $tmp = $rMin;
                $rMin = $rMax;
                $rMax = $tmp;
            }
            $value -= $rMin;
            $value /= ($rMax - $rMin);

            return self::incompleteBeta($value, $alpha, $beta);
        }

        return Functions::VALUE();
    }
public static function BETADIST($value, $alpha, $beta, $rMin = 0, $rMax = 1)
    {
        $value = Functions::flattenSingleValue($value);
        $alpha = Functions::flattenSingleValue($alpha);
        $beta = Functions::flattenSingleValue($beta);
        $rMin = Functions::flattenSingleValue($rMin);
        $rMax = Functions::flattenSingleValue($rMax);

        if ((is_numeric($value)) && (is_numeric($alpha)) && (is_numeric($beta)) && (is_numeric($rMin)) && (is_numeric($rMax))) {
            if (($value < $rMin) || ($value > $rMax) || ($alpha <= 0) || ($beta <= 0) || ($rMin == $rMax)) {
                return Functions::NAN();
            }
            if ($rMin > $rMax) {
                $tmp = $rMin;
                $rMin = $rMax;
                $rMax = $tmp;
            }
            $value -= $rMin;
            $value /= ($rMax - $rMin);

            return self::incompleteBeta($value, $alpha, $beta);
        }

        return Functions::VALUE();
    }
BETADIST.

Returns the beta distribution.

@param float $value Value at which you want to evaluate the distribution
@param float $alpha Parameter to the distribution
@param float $beta Parameter to the distribution
@param mixed $rMin
@param mixed $rMax

@return float