Derive the mathematical relation between

Derive the mathematical relation between
refractive indices n1 and n2 of two radii and radius
of curvature R for refraction at a convex spherical
surface. Consider the object to be a point since lying on the principle axis in rarer medium of
refractive index n1 and a virtual image formed in
the rarer medium of refractive index n1 Hence,
derive lens maker’s formula.
(ii) Light from a point source in air falls on a convex
spherical glass surface of refractive index 1.5 and radius of curvature 20 cm. The distance of light source from the glass surface is 100 cm. At what position is the image formed ?

(i) Let an object O is placed at a distance u from convex spherical refracting surface whose virtual image forms at I at a distance v from surface. Let R is the radius of curvature of surface.