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MATHEMATICScot x cot 2x - cot 2x cot 3x - cot 3x cot x = 1 |
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Answer» ONG>Answer: cot x cot 2x - cot 2x cot 3X - cot 3x cot 4X = cot x cot 2x - cot 3x (cot 2x+ cot x) = cot x cot 2x - cot (2x+x)(cot 2x+ cot x) [ as cot(A+B)= cotAcotB cotAcotB−1
] = cot x cot 2x-( cotx+cot2x cot2xcotx−1
)(cot 2x+ cot x) = cot x cot 2x- (cot 2x cot x-1) = cot x cot 2x- cot 2x cot x+1 = 1 Hence, proved |
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