57.cos^(-1)(cos(8 pi)/(5))=

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

The value of cos[(1)/(2)cos^(-1)cos((14 pi)/(5))]is(a)cos((2 pi)/(5))(b)cos(-(7 pi)/(5))(c)sin((pi)/(10))(d)-cos((3 pi)/(5))

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

The value of cos[1/2cos^(-1)(cos(-(14pi)/5))]\ is/are a. cos(-(7pi)/5) b. sin(pi/(10)) c. cos((2pi)/5)\ d. -cos((3pi)/5)

The value of cos[1/2cos^(-1)(cos(-(14pi)/5))]\ is/are a. cos(-(7pi)/5) b. sin(pi/(10)) c. cos((2pi)/5)\ d. -cos((3pi)/5)

The value of cos(pi)/(5)cos.2(pi)/(5)cos4(pi)/(5)cos8(pi)/(5)=

cos(pi/5)cos((2pi)/5)cos((4pi)/5)cos((8pi)/5)=

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

Prove that: (cos pi)/(5)(cos(2 pi))/(5)(cos(4 pi))/(5)(cos(8 pi))/(5)=(-1)/(6)

Prove that: cos(pi/5)cos((2pi)/5)cos((4pi)/5)cos((8pi)/5)=(-1)/16