A piece of electronic circuitry embedded in a layer of diamond (left(n_{text {diamond }}=2.42 ight.) ) emits

A piece of electronic circuitry embedded in a layer of diamond \(\left(n_{\text {diamond }}=2.42\right.\) ) emits light. The diamond is covered by a coating of flint glass \(\left(n_{\text {flint }}=1.65\right)\). The interface between the two materials is flat, as is the interface between the flint glass and the surrounding air. The two interfaces are parallel. Relative to the direction normal to both interfaces, what are (a) the greatest angle at which light emitted in the diamond layer can enter the flint glass and \((b)\) the greatest angle at which light emitted in the diamond layer travels through the flint glass and enters the surrounding air?