" Sin "27^(@)sec63^(@)" an thoretid affor "

Evaluate sin 27 ^(@) sin 63 ^(@) - cos 63^(@) cos 27 ^(@)

The value of sin3^(@)sin27^(@)sin33^(@)sin57^(@)sin63^(@)sin87^(@) can be equal to -

(cos ec ^ (2) (63 ^ (@)) + tan ^ (2) (24 ^ (@))) / (cot ^ (2) (66 ^ (@)) + sec ^ (2) (27 ^ (@))) + (sin ^ (2) (63 ^ (@)) + cos (63 ^ (@)) sin (27 ^ (@)) + sin (27 ^ (@)) sec (63 ^ (@))) / (2 [cos ec ^ (2) (65 ^ (@)) - tan ^ (2) (25 ^ (@))])

It is given that sin54^(@)=(sqrt(5)+1)/(4), the value of (64sin^(4)27^(@)-64sin^(2)27^(@)+6)^(2)-15(sin^(2)27^(@)+sin^(2)63^(@)) 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^(@) =