`(cosalpha+cosbeta)^2+(sinalpha-sinbeta)^2=4cos^2(alpha+beta)/2`

Prove that: (cosalpha-cosbeta)^2+(sinalpha-sinbeta)^2=4sin^2((alpha-beta)/2)^(\ )

If (cosalpha+cosbeta)^2+(sinalpha+sinbeta)^2=lambdacos^2((alpha-beta)/2), write the value of lambdadot

Prove that (Cosalpha-Cosbeta)^(2)+(Sinalpha-Sinbeta)^(2)=4Sin^(2)((alpha-beta)/2)

If A=[(0,sin alpha, sinalpha sinbeta),(-sinalpha, 0, cosalpha cosbeta),(-sinalpha sinbeta, -cosalphacosbeta, 0)] then (A) |A| is independent of alpha and beta (B) A^-1 depends only on beta (C) A^-1 does not exist (D) none of these

If A=[(0,sin alpha, sinalpha sinbeta),(-sinalpha, 0, cosalpha cosbeta),(-sinalpha sinbeta, -cosalphacosbeta, 0)] then (A) |A| is independent of alpha and beta (B) A^-1 depends only on beta (C) A^-1 does not exist (D) none of these

If cosalpha+cosbeta=0=sinalpha+sinbeta" then "cos2alpha+cos2beta

If cosalpha+cosbeta=0=sinalpha+sinbeta , then cos2alpha+cos2beta=?

If cosalpha+cosbeta=0=sinalpha+sinbeta, then cos2alpha+cos2beta is equal to (a) -2"sin"(alpha+beta) (b) -2cos(alpha+beta) (c) 2"sin"(alpha+beta) (d) 2"cos"(alpha+beta)

If cosalpha+cosbeta=0=sinalpha+sinbeta, then cos2alpha+cos2beta is equal to (a) -2"sin"(alpha+beta) (b) -2cos(alpha+beta) (c) 2"sin"(alpha+beta) (d) 2"cos"(alpha+beta)

If cosalpha+cosbeta=0=sinalpha+sinbeta,cos2alpha+cos2beta is equal to a) -2sin(alpha+beta) b) 2cos(alpha+beta) c) 2sin(alpha-beta) d) -2cos(alpha+beta)