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

Simplify (sinalpha+sinbeta)/(cosalpha-cosbeta)+(cosalpha+cosbeta)/(sinalpha-sinbeta)

Prove by vector metod the following formula of plane trigonometry cos(alpha-beta)=cosalpha cosbeta+sinalpha sinbeta

Prove by vector metod the following formula of plane trigonometry cos(alpha-beta)=cosalpha cosbeta+sinalpha sinbeta

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=2/3 and sinalpha+sinbeta=2/5 then find the vvalue of tan((alpha+beta)/2)

(cosalpha)/(cosbeta)=n and (sinalpha)/(sinbeta)=m , find (m^(2)-n^(2))sin^(2)beta

If cosalpha+cosbeta=1/3 and sinalpha+sinbeta=1/4 ,show that tan ((alpha+beta)/2)=3/4

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

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