" 3.cos "^(-1)(cos(7 pi)/(6))" an "41+arctan(4)/(8)

cos(cos^(-1)cos((8 pi)/(7))+tan^(-1)tan(8(pi)/(7))) has the value equal to -

cos ^ (4) ((pi) / (8)) + cos ^ (4) ((3 pi) / (8)) + cos ^ (4) ((5 pi) / (8)) + cos ^ ( 4) ((7 pi) / (8)) =

cos (cos^-1 cos((8pi)/7) +tan^-1 tan((8pi)/7)) has the value equal to -

The value of (1+cos (pi)/(8))(1+cos (3 pi)/(8))(1+cos (5 pi)/(8))(1+cos (7 pi)/(8)) is

cos (cos^-1 cos((8pi)/7) +tan^-1 tan(8pi/7)) has the value equal to -

cos. (pi)/(7) + cos. (2pi)/(7) + cos. (3pi)/(7) + cos. (4pi)/(7) + cos. (5pi)/(7) + cos. (6pi)/(7)=

Show that (1+ cos. (pi)/(8))(1+cos. (3pi)/(8))(1+ cos. (5pi)/(8))(1+ cos .(7pi)/(8))=(1)/(8)

Prove that (1+"cos"(pi)/(8))(1+"cos"(3pi)/(8))(1+"cos"(5pi)/(8))(1+"cos"(7pi)/(8))=(1)/(8) .