[填空题]
A parallel beam of light8 mwg;mzh8f/ fs/lr*i containing 8frr y9 kjd2(+:; mrmxz/tjb xtwo wavelengths, 420 nm and 650 nm, enters a silicate flint glass rb29xzjrmr+ tjx/mk8:f d ;y(equilateral prism (Fig. 24–58).
(a) What is the angle between the two beams leaving the prism? $^{\circ}\,$
(b) Repeat part (a) for a diffraction grating with $^{\circ}\,$
