The refractive index of a medium (2) with respect to medium (1) is x and refractive index of medium (2) with respect to medium (3) is 'y' then what is the refractive to index of the medium (3) with respect to medium (1).

Explanation

`.^(1)mu_(3) = x//y`
`.^(1)mu_(2)=x,. ^(3)mu_(2) = y`
`.^(1)mu_(3) = mu_(3)/mu_(1) = mu_(3)/mu_(1) xx mu_(2)/mu_(2) = mu_(3)/mu_(2) xxmu_(2)/mu_(1) = .^(2)mu_(3) xx. ^(1)mu_(2)`
` rArr(.^(1)mu_(2))/(.^(3)mu_(2)) = x/y`