[填空题]
Unpolarized light falls on two polarizer sheets whoscgy9mxr0 -kr 1e transmist0l .w h-dcqtxg jtlwp28bl (wp2:5g/sion axes are at right angles. A third polarizer is placed between the first two so that its 8jc: tlx.g 2gw0ppb5tqww dll(t h -2/axis makes a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted? $I_0$
(b) What if the third polarizer is in front of the other two?
