" 15."tan63^(@)*tan27^(@)=1

The value of tan 81^(@) - tan 63^(@) - tan 27^(@)+ tan 9^(@) is equal to

The vlaue of tan 81^(@) - tan 63^(@) - tan 27^(@)+ tan 9^(@) is equal to

tan 9^(@) - tan 27^(@) - tan 63^(@) + tan 81^(@)=.................. ??

tan 9^(@) - tan 27^(@) - tan 63^(@) + tan 81^(@)=.................. ??

tan 9^(@) - tan 27^(@) - tan 63^(@) + tan 81^(@) =

(1+tan18^(@)) (1+tan27^(@))=

Prove that: (i) "sin"^(2)24^(@)-"sin"^(2)6^(@)=(1)/(8)(sqrt(5)-1) (ii) "tan"9^(@)-"tan"27^(@)-"tan"63^(@)+"tan"81^(@)=4 .

Let the set of all a in R such that the equation cos2x+a sin x=2a-7 has a solution be [p,q] and r=tan9^(@)-tan27^(@)-(1)/(cot63^(@))+tan81^(@) ,then pqr is equal to