If `cosalpha+cosbeta=a ,sinalpha+sinbeta=b and alpha-beta=2theta,` then `(cos3theta)/(costheta)=`

If cosalpha+cosbeta=a,sinalpha+sinbeta=band alpha-beta=2theta , then (cos3theta)/(costheta) =

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

(cosalpha+cosbeta)^2+(sinalpha+sinbeta)^2 =

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

If sinalpha+sinbeta=a ,cosalpha+cosbeta=b=>sin(alpha+beta) =

sinalpha+sinbeta=a ,cosalpha+cosbeta=b=>sin(alpha+beta)

If cos alpha + cosbeta=a, sinalpha + sinbeta=b and theta is the arithmetic mean between alpha and beta , then (sin2theta + cos 2theta) is equal to :

If cos alpha + cosbeta=a, sinalpha + sinbeta=b and theta is the arithmetic mean between alpha and beta , then (sin2theta + cos 2theta) is equal to :

If cosalpha+2cosbeta+3cosgamma=sinalpha+2sinbeta+3singamma=0 and alpha+beta+gamma=0 , then cos3alpha+8cos3beta+27sin3gamma=

If cosalpha+cosbeta=1/3 and sinalpha+sinbeta=1/4 prove that cos(alpha-beta)/2=+-5/24