Question

Surfaces of a thin equiconvex glass lens have radius of curvature R. Paraxial rays are incident on it. If the final image is formed after n internal reflections. Calculate distance of this image from pole of the lens. Refractive index of glass is μ.

Answer 1

The rays will first get refracted, then n-times reflected and finally again refracted. So, using 

for first refraction, we have

For first reflection let us use