Here are step-by-step instructions on how to construct the optical axis:
- Construct the tangents of the ellipse OM and OL (note that M is the image of the point T mentioned in the earlier hints).
- Construct the image of the farthest-from-O point on the circle (the point A from the earlier hints).
- Construct the point V where all the rays parallel to t (the ray that touches the circle at the point A) converge after passing the lens.
- Draw the image of the line AT.
- Using the previous hints, draw a line u through O that is parallel to AT.
- Hence find the point U where all the lines parallel to AT converge after passing the lens.
- Hence find the focal plane and the optical axis.
Please submit the solution to this problem via e-mail to physcs.cup@gmail.com.