Find the fastest path from Point C to Point D! Only one rule: You have to touch the blue surface on the way!
Instructions: 1) Choose the position of Point C and the position of Point D. 2) Slide the Point E along the surface until you find the fastest Total Time. 3) Check the Box "Show Lot and Angles". What condition do you discover for the fastest path? 4) Move the Point E, again, and observe what happens with the angles. 5) Explore other positions for the Points C and D and find the fastest path. 6) Optional: You can change the velocity of light (c_1), if you wish.