(cot10-1)(cot35-1)=2 prove it

∵ 10 + 35 = 45

∴ cot ( 10 + 35 ) = cot 45

∴ ( cot 10 + cot 35 ) / ( cot 10 cot 35 - 1 ) = 1

∴ cot 10 + cot 35 = cot 10 cot 35 - 1

∴ cot 10 cot 35 - cot 10 - cot 35 = 1

∴ cot 10 ( cot 35 - 1 ) - cot 35 + ( 1 ) = 1 + ( 1 )

∴ cot 10 ( cot 35 - 1 ) - ( cot 35 - 1 ) = 2

∴ ( cot 10 - 1 )( cot 35 -1 ) = 2 ............................... Q.E.D.
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What is your question? Can't you calculate the cot of 10 and 35?