Let ` f( theta) = ( cos theta - "cos" (pi)/(8))(cos theta - "cos" (3 pi)/(8))(cos theta - "cos" (5 pi)/(8) )(cos theta - "cos" (7pi)/(8))` then :

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

Solve the equation z^8+1=0 and deduce that cos4theta=8(costheta-cos(pi/8))(costheta-cos((3theta)/3))(costheta- cos((5pi)/8))(costheta-cot((7pi)/8))

16(costheta-cos""(pi)/8)(costheta-cos""(3pi)/8)(costheta-cos""(5pi)/8)(costheta-cos""(7pi)/8)= lamda cos 4 theta the value of lamda is

16(costheta-cospi/8)(costheta-cos(3pi)/8)(costheta-cos(5pi)/8)(costheta-cos(7pi)/8)=lambdacos4theta, then the value of lambda is _____.

16(costheta-cospi/8)(costheta-cos(3pi)/8)(costheta-cos(5pi)/8)(costheta-cos(7pi)/8)=lambdacos4theta, then the value of lambda is _____.

Prove that cos theta + cos ((2pi)/(3)- theta)+ cos ((2pi)/(3)+ theta)=0

Prove that: 2cos theta cos((pi)/(3)+theta)cos((pi)/(3)-theta)=cos3 theta

If cos theta = cos 5pi//4 , then theta =

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

16(costheta-cos(pi/8))(costheta-cos((3pi)/8))(costheta-cos((5pi)/8)) (costheta-cos((7pi)/8))= lambdacos4theta, then the value of lambda is _____.