`cos(pi/15)cos((2pi)/15)cos((3pi)/15)cos((4pi)/15)cos((5pi)/15)cos((6pi)/15)cos((7pi)/15)` = `1/2^7`

If the value of "cos"pi/15"cos"(2pi)/15"cos"(3pi)/15"cos"(4pi)/15"cos"(5pi)/15"cos"(6pi)/15"cos"(7pi)/15 is (1)/(2^(k)) , then which of the following is true ?

cos((pi)/(15))cos((2 pi)/(15))cos((pi)/(5))cos((4 pi)/(15))cos((2 pi)/(5))cos((7 pi)/(15)) is equal to

cos""(2pi)/(15)cos""(4pi)/(15)cos""(8pi)/(15)cos""(16pi)/(15)=(1)/(16)

cos ""(2pi)/( 15) cos ""(4pi)/(15) cos ""(8pi)/(15) cos ""(16pi)/(15)=

The value of cos((pi)/(7))+cos((2 pi)/(7))+cos((3 pi)/(7))+cos((4 pi)/(7))+cos((5 pi)/(7))+cos((6 pi)/(7))+cos((7 pi)/(7)) is 1(b)-1(c)0(d) none of these

cos ((pi) / (15)) cos ((2 pi) / (15)) cos ((3 pi) / (15)) cos ((4 pi) / (15)) cos ((5 pi) / (15)) cos ((6 pi) / (15)) cos ((7 pi) / (15)) = (1) / (1)

Prove that :16cos2(pi)/(15)cos4(pi)/(15)cos8(pi)/(15)cos16(pi)/(15)=1

Show that 16cos((2 pi)/(15))cos((4 pi)/(15))cos((8 pi)/(15))cos((16 pi)/(15))=1

cos.(2pi)/(7)+cos.(4pi)/(7)+cos.(6pi)/(7)

The value of cos((pi)/(15))cos((2 pi)/(15))cos((4 pi)/(15))cos((8 pi)/(15))=