When a monochromatic light ray is incident on a medium of refracive index`mu`with angle of incidence `theta_(1)`,the angle of refraction is `theta_(r).`if `theta_(i)` is changed slightly by`Deltatheta_(i)`,then the corresponding change in `theta_(r)`will be-

Options

A. `Deltatheta_i`
B. `muDeltatheta_i`
C. `1/mu.(costheta_i)/(costheta_r).Deltatheta_1`
D. `mu.(costheta_i)/(costheta_r).Deltatheta_i`

Answer

C