Calculate angle between two Latitude/Longitude points

Question

Is there a way to calculate angle between two Latitude/Longitude points?

What I am trying to achieve is to know where the user is heading. For example, user is head

Answer 1

Considering Nayanesh Gupte's answer and its comments. I've changed some part of the code and wrote it in PHP.

• latitude and longitude have been converted to radians inside the function.

Here is the function:

function angleFromCoordinate($lat1, $long1, $lat2, $long2) {

    $lat1 = deg2rad($lat1);
    $lat2 = deg2rad($lat2);
    $long1 = deg2rad($long1);
    $long2 = deg2rad($long2);

    $dLon = $long2 - $long1;

    $y = sin($dLon) * cos($lat2);
    $x = cos($lat1) * sin($lat2) - sin($lat1) * cos($lat2) * cos($dLon);

    $brng = atan2($y, $x);

    $brng = $brng * 180 / pi();
    $brng = fmod($brng + 360, 360);

    return $brng;
}