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If Cot x/Cot y = A and Cosec x/Cosec y = B, then the value of Cosec y in terms of A and B.1.√((1 – A2)/(B2 – A2))2. (1 – A2)/(A2 – B2)3. A/(B2 – A2)4. (1 – B2)/(B2 – A2) |
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Answer» Correct Answer - Option 1 : √((1 – A2)/(B2 – A2)) Given Cot x/Cot y = A and Cosec x/Cosec y = B Concept Cosec2 A – Cot2A = 1 Calculation Cot x = A Cot y Squaring on both sides Cot2x = A2Cot2y ⇒ Cosec 2x – 1 = A 2 (Cosec 2 y – 1) ---- (1) Cosec x = B Cosec y Squaring on both sides ⇒ Cosec 2x = B 2Cosec 2 y ---- (2) From (1) and (2) B2Cosec2y – 1 = A2Cosec2y – A2 ⇒ B2Cosec2y – A2Cosec2y = - A2 + 1 ⇒ Cosec2y(B2– A2) = - A2+ 1 ⇒ Cosec y = √((1 – A2)/(B2 – A2)) |
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