If cos(A + B) = 0 and sin(A – B) = ½ , then the value of B is:
(Given 0o < A,B < 90o)
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e 30o
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Understanding Tricks |
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Application ⇒ cos(A + B) = 0 ⇒ cos(A + B) = cos90 ⇒ (A + B) = 90 .........) And ⇒ sin(A – B) = ½ ⇒ sin(A – B) = sin30 ⇒ (A – B) = 30 ........ii) |
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Now From eq i) and eq ii) B = 30 |