(v) `cos^-1(cos((9pi)/8))`

The principal solution of cos^(-1)(cos((9pi)/4)) is

cos^(-1) (cos 8pi/5)

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

The value of sin^(-1)((cos(pi/9))

Which of the following quantities are rational? (a) sin((11 pi)/(12))sin((5 pi)/(12))( b) cos ec((9 pi)/(10))sec((4 pi)/(5))(c)sin^(4)((pi)/(8))+cos^(4)((pi)/(8))(d)(1+(cos(2 pi))/(9))(1+(cos(4 pi))/(9))(1+(cos(8 pi))/(9))

cos ((pi) / (8)) cos ((3 pi) / (8)) cos ((5 pi) / (8)) cos ((7 pi) / (8)) =

Simplify: [(1+ (sin pi) / (8) + i (cos pi) / (8)) / (1+ (sin pi) / (8) -i (cos pi) / (8))] ^ ((1) / (2))

16(cos theta-cos(pi)/(8))(cos theta-cos(3 pi)/(8))(cos theta-cos(5 pi)/(8))(cos theta-cos(7 pi)/(8))=lambda cos4 theta then the value of lambda is

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