Cot2A.cosec2B-cot2B.cosec2A=cot2A-cot2B
LHS = cot2A cosec2B - cot2B cosec2A
= cot2A(1 + cot2B) - cot2B(1 + cot2A)
= cot2A + cot2A cot2B - cot2B - cot2A cot2B
= cot2A - cot2B = RHS
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Cot2A.cosec2B-cot2B.cosec2A=cot2A-cot2B
LHS = cot2A cosec2B - cot2B cosec2A
= cot2A(1 + cot2B) - cot2B(1 + cot2A)
= cot2A + cot2A cot2B - cot2B - cot2A cot2B
= cot2A - cot2B = RHS