\[\left( 1+\cos \frac{\pi }{8} \right)\,\left( 1+\cos \frac{3\pi }{8} – McqOptions

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1.	\[\left( 1+\cos \frac{\pi }{8} \right)\,\left( 1+\cos \frac{3\pi }{8} \right)\,\left( 1+\cos \frac{5\pi }{8} \right)\,\left( 1+\cos \frac{7\pi }{8} \right)=\] [IIT 1984; WB JEE 1992]
A.	\[\frac{1}{2}\]
B.	\[\frac{1}{4}\]
C.	\[\frac{1}{8}\]
D.	\[\frac{1}{16}\]
Answer» D. \[\frac{1}{16}\]

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