If `sinalpha+sinbeta=a` and `cosalpha+cosbeta=b ,` prove that `tan((alpha-beta)/2)=+-sqrt((4-a^2-b^2)/(a^2+b^2))` .

If sinalpha+sinbeta and cosalpha+cosbeta=b , prove that tan(alpha-beta)/2=+-sqrt((4-a^2-b^2)/(a^2+b^2)) .

If sinalpha+sinbeta=a and cosalpha+cosbeta=b prove that: cos(alpha-beta)=((a^2+b^2-2)/2)

If sinalpha+sinbeta=a and cosalpha+cosbeta=b prove that: cos(alpha-beta)=((a^2+b^2-2)/2)

If sinalpha+sinbeta=a and coslapha+cosbeta=b then prove that sin(alpha+beta)=(2ab)/(a^2+b^2)

If sinalpha+sinbeta=a\ and\ cosalpha-cosbeta=b , then tan((alpha-beta)/2)= a. -a/b b. -b/a c. sqrt(a^2+b^2) d. none of these

If sin alpha+sin beta=a\ a n d\ cosalpha+cosbeta=b , show that : sin(alpha+beta)=(2"a b")/(a^2+b^2)

If sinalpha-sinbeta=a and cosalpha+cosbeta=b then write the value of "cos"(alpha+beta) .

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

If sin alpha+sin beta=a\ a n d\ cosalpha-cosbeta=b , then tan(alpha-beta)/2= -a/b b. b/a c. sqrt(a^2+b^2) d. none of these

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