For all the math geniuses out there...given two lat/lon points (point A and point B), what is the simplest way to find the vector needed to reach point B from point A. For example, the vector needed to reach 36, -85 from 36, -82 would be 270°. I am not entirely sure if "vector" is the technically correct term so if there is a more accurate term, comment and let me know. The fact that the earth is a sphere is throwing me off...I feel as if I could tackle this problem if given a plane but the sphere complicates it too much for me. A chunk of code would be ideal but a simple algorithm that I can translate into code myself is perfectly fine also.
var y = Math.sin(dLon) * Math.cos(lat2); var x = Math.cos(lat1)*Math.sin(lat2) - Math.sin(lat1)*Math.cos(lat2)*Math.cos(dLon); var brng = Math.atan2(y, x).toDeg();
The above link has a wealth of useful information beyond this for related calculations.
As your question states, this is the simplest method - since the Earth is not a true sphere this calculation will not be 100% accurate, but it is a close approximation.