[填空题]
At what angle should the axes .)vu wo4.ezvy4 8 uciwof two Psfo,m6r,ipo(a-;tbg .z d bw*olaroids be placed so as to reduce the intensity of thewr;f(io. b z, d*tmbs6-ag ,po incident unpolarized light to
(a) $\frac{1}{3}$ , $^{\circ}\,$
(b) $\frac{1}{10}$ ? $^{\circ}\,$
