InterviewSolution
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InterviewSolution
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The value of sin `10^(@)` sin `30^(@)` sin `50^(@)` sin `70^(@)` isA. `(1)/(36)`B. `(1)/(32)`C. `(1)/(16)`D. `(1)/(18)` |
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Answer» Correct Answer - C We have, sin `10^(@) sin 50^(@) sin 70^(@)` `=sin (30^(@))[sin(10^(@))sin(50^(@))sin (70^(@))]` `=(1)/(2)[sin(10^(@))sin(60^(@)-10^(@))sin(60^(@)+10^(@))]` `=(1)/(2)[(1)/(4)sin(3(10^(@)))] " "[because sin theta sin (60^(@)-theta)sin(60^(@)+theta)=(1)/(4)sin3 theta]` `=(1)/(8)sin 30^(@) = (1)/(8) xx (1)/(2) = (1)/(16)` |
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