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Question : 64 of 160
Marks:
+1,
-0
Solution:
[1−cos()−cos() +cos().cos()] ={1(1−cos‌)−cos()2.(1−cos())} ={(1−cos‌)(1−cos())} [∵(1−cos‌θ)=2sin2] ={(2sin2())(2sin2())} =32()××()2× ()2()2 =.1.1= {∵‌frac‌=1}
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