`cos4 2^(@)+cos7 8^(@)+cos16 2^(@)=`

Prove that cos 2 0^(@)cos4 0^(@)cos6 0^(@)cos8 0^(@)=1/16

Prove that cos^(2)76^(@)+cos^(2)16^(@)-cos76^(@)cos16^(@)=(3)/(4)

2sin ^ (2) (8 (1 ^ (@)) / (2)) + 4cos16 ^ (@) sin (7 (1 ^ (@)) / (2)) sin (8 (1 ^ (@)) / (2)) + cos32 ^ (@) =

cos A * cos2A * cos4A * cos8A * cos16A * cos32A = (sin (64A)) / (64sin A)

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

If f(x) = cos x cos 2x cos 4x cos (8x). cos 16x then find f' (pi/4)

If f(x) = cos x cos 2x cos 4x cos (8x). cos 16x then find f' (pi/4)

If f(x) = cos x cos 2x cos 4x cos (8x). cos 16x then find f' (pi/4)

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

cos ^ (2) ((pi) / (8)) + cos ^ (2) ((3 pi) / (8)) + cos ^ (2) ((5 pi) / (8)) + cos ^ ( 2) ((7 pi) / (8)) = 2