Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Engineering.php
public static function IMDIV($complexDividend, $complexDivisor)
    {
        $complexDividend = Functions::flattenSingleValue($complexDividend);
        $complexDivisor = Functions::flattenSingleValue($complexDivisor);

        $parsedComplexDividend = self::parseComplex($complexDividend);
        $parsedComplexDivisor = self::parseComplex($complexDivisor);

        if (($parsedComplexDividend['suffix'] != '') && ($parsedComplexDivisor['suffix'] != '') &&
            ($parsedComplexDividend['suffix'] != $parsedComplexDivisor['suffix'])
        ) {
            return Functions::NAN();
        }
        if (($parsedComplexDividend['suffix'] != '') && ($parsedComplexDivisor['suffix'] == '')) {
            $parsedComplexDivisor['suffix'] = $parsedComplexDividend['suffix'];
        }

        $d1 = ($parsedComplexDividend['real'] * $parsedComplexDivisor['real']) + ($parsedComplexDividend['imaginary'] * $parsedComplexDivisor['imaginary']);
        $d2 = ($parsedComplexDividend['imaginary'] * $parsedComplexDivisor['real']) - ($parsedComplexDividend['real'] * $parsedComplexDivisor['imaginary']);
        $d3 = ($parsedComplexDivisor['real'] * $parsedComplexDivisor['real']) + ($parsedComplexDivisor['imaginary'] * $parsedComplexDivisor['imaginary']);

        $r = $d1 / $d3;
        $i = $d2 / $d3;

        if ($i > 0.0) {
            return self::cleanComplex($r . '+' . $i . $parsedComplexDivisor['suffix']);
        } elseif ($i < 0.0) {
            return self::cleanComplex($r . $i . $parsedComplexDivisor['suffix']);
        }

        return $r;
    }
public static function IMDIV($complexDividend, $complexDivisor)
    {
        $complexDividend = Functions::flattenSingleValue($complexDividend);
        $complexDivisor = Functions::flattenSingleValue($complexDivisor);

        $parsedComplexDividend = self::parseComplex($complexDividend);
        $parsedComplexDivisor = self::parseComplex($complexDivisor);

        if (($parsedComplexDividend['suffix'] != '') && ($parsedComplexDivisor['suffix'] != '') &&
            ($parsedComplexDividend['suffix'] != $parsedComplexDivisor['suffix'])
        ) {
            return Functions::NAN();
        }
        if (($parsedComplexDividend['suffix'] != '') && ($parsedComplexDivisor['suffix'] == '')) {
            $parsedComplexDivisor['suffix'] = $parsedComplexDividend['suffix'];
        }

        $d1 = ($parsedComplexDividend['real'] * $parsedComplexDivisor['real']) + ($parsedComplexDividend['imaginary'] * $parsedComplexDivisor['imaginary']);
        $d2 = ($parsedComplexDividend['imaginary'] * $parsedComplexDivisor['real']) - ($parsedComplexDividend['real'] * $parsedComplexDivisor['imaginary']);
        $d3 = ($parsedComplexDivisor['real'] * $parsedComplexDivisor['real']) + ($parsedComplexDivisor['imaginary'] * $parsedComplexDivisor['imaginary']);

        $r = $d1 / $d3;
        $i = $d2 / $d3;

        if ($i > 0.0) {
            return self::cleanComplex($r . '+' . $i . $parsedComplexDivisor['suffix']);
        } elseif ($i < 0.0) {
            return self::cleanComplex($r . $i . $parsedComplexDivisor['suffix']);
        }

        return $r;
    }
IMDIV.

Returns the quotient of two complex numbers in x + yi or x + yj text format.

Excel Function:
IMDIV(complexDividend,complexDivisor)

@param string $complexDividend the complex numerator or dividend
@param string $complexDivisor the complex denominator or divisor

@return string