InterviewSolution
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InterviewSolution
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The general solution of the equation `8 cos x cos 2x cos 4x = sin 6x//sin x` isA. `x=(n pi//7)+(pi//21), AA n in Z`B. `x=(2pi//7)+(pi//14), AA n in Z`C. `x=(n pi//7)+(pi//14), AA n in Z`D. `x=(n pi)+(pi//14), AA n in Z` |
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Answer» Correct Answer - C The given equation is `8 sin x cos x cos 2x cos 4 x= sin 6x (sin x ne 0)` `rArr sin 8x= sin 6x` `rArr 2 cos 7x sin x =0` As `sin x ne 0, cos 7x=0` or `7x=n pi +pi//2, n in Z` i.e. `x= n pi//7+pi//14, n in Z` |
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