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Question : 10 of 160
Marks:
+1,
-0
Solution:
The value of the expression is calculated as
(sin‌−i‌cos‌)‌‌=−i‌[cos(‌)−‌‌sin(‌)] ‌‌=−i‌[cos(‌)+i‌sin(‌)] ‌‌=−i[e‌]...(1) Now from the given condition.
1+e‌+e‌+e‌+e‌+e‌+e‌=0 1+ei(2π)=0 ei(2π)=−1 From equation (1) and (2)
(sin‌−i‌cos‌)=−i(−1)=i
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