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CosecA+cot A=2/3COS A=?? |
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Answer» Answer: Step-by-stHello Friend, Here, → cosec A - COT A = 3/2 ----(1) → We know that, cosec²A - cot²A = 1 So, (cosec A + cot A)(cosec A - cot A) = 1 So, (cosec A + cot A)(3/2) = 1 (From (1)) So, cosec A + cot A = 2/3 ----(2) → Now , ADD (1) and (2) So, cosec A - cot A = 3/2 cosec A + cot A = 2/3 ---------------------------------- So, 2 cosec A = (3/2) + (2/3) So, 2 cosec A = 13/6 So, cosec A = 13/12 So, sin A = 1/cosec = 12/13 → Now, we have sin A = 12/13 sin A is positive. This means that A lies in either First or Second Quadrant. We can find cot A easily to check which quadrant A lies in. Putting cosec A = 13/12 in (2) So, cosec A + cot A = 2/3 So, 13/12 + cot A = 2/3 So, cot A = 2/3 - 13/12 So, cot A = (8-12)/12 So, cot A = -5/12 • Now, cot A is negative. So A can either be in Second or Fourth Quadrant. But, as sin A is also positive , A must lie in Second Quadrant. → Now, cot A = cos A/sin A So, cos A = cot A × sin A So, cos A = (-5/12) × (12/13) So, cos A = -5/13 → Thus, cos A = -5/13, and A lies in Second Quadrant. Hope it HELPS.....plzz mark me on brainliests
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