`(1+cot78^(@))(1+cot57^(@))=......`

(1-cot200^(@))(1-cot25^(@))=

(1-cot200^(@))(1-cot25^(@))

If (1-cot 1^(@))*(1-cot2^(@))*(1-cot3^(@))...(1-cot44^(@))=2^(n) , then (n)/(11) is equal to

(1+cot85^(@))/(cot85^(@)*)(1+cot95^(@))/(cot95^(@)*)(1+cot130^(@))/(cot130^(@))(1+cot140^(@))/(cot140^(@)=)

Find the value of (1-cot35^(@))*(1-cot65^(@))*(1-cot160^(@))*(1-cot190)

The sum of the series cot^(-1)2+cot^(-1)8+cot^(-1)18+cot^(-1)32.........

The sum of cot^(-1)(3/4)+cot^(-1)(7/4)+cot^(-1)(19/4)+ cot^(-1)(39/4)......oo