Suppose A light ray starts

Question

at the point A = (0,a) in an uniform medium 1 where the speed of light is c1 and then passes through an uniform medium 2 where the speed of light is c2 reaching point B = (d, −b). The line separating the two media is the x-axis;

HINTS ONLY
1) what is the shortest path of the light ray from A to B
2) what time is needed for the light ray to travel along the first path - in medium 1
3) same thing as (2) part 2 path

Answer 1

try this discussion:

http://dev.physicslab.org/Document.aspx?doctype=3&filename=GeometricOptics_LeastTime.xml