A point source of light is placed inside water and a thin converging lens ofrefractive index `mu_(2)` is placed just outside the plane surface of water. The image of the source is formed at a distance x from the surface of water. If the lens is now placed just inside water and the image is now formed at a distances' from the surface of water, show that
`(1)/(x) -(1)/(x_(1)) = (mu_(1)-1)/(mu_(2)-1) xx (1)/(f)`,
Where f is the focal length of the lens and `mu_(1)` is the refractive index of water.