`sin theta + sin phi = a`,`cos theta + cos phi=b` then prove `tan [(theta -phi)/2]=+-sqrt[(4-a^2-b^2)/(a^2+b^2)]`

If sin theta + sin phi = a, cos theta + cos phi = b prove that tan ((theta-phi)/2 )=pm sqrt((4-a^(2)-b^(2))/(a^(2)+b^(2)))

If sin theta - sin phi = a and cos theta + cos phi = b then prove that cos(theta + phi) = (a^(2)+b^(2) -2)/2

If sin theta+sin phi=a and cos theta+cos phi=b find the value of tan((theta-phi)/(2))

If sin theta +sin phi=a and cos theta +cos phi =b then prove cos (theta +phi)=(b^(2)-a^(2))/(b^(2)+a^(2))

If sin theta+ sin phi= a and cos theta+ cos phi= b , find : sin (theta+ phi) .

If sin 2 theta + sin 2 phi =1/2 and cos 2 theta + cos 2 phi =3/2, then cos ^(2) (theta - phi)=

If sin 2 theta + sin 2 phi =1/2 and cos 2 theta + cos 2 phi =3/2, then cos ^(2) (theta - phi)=

If sin theta+ sin phi= a and cos theta+ cos phi= b , find : cos (theta- phi) .

If sin theta+ sin phi= a and cos theta+ cos phi= b , find : cos (theta+ phi) .

If sin 2theta+sin 2phi=1//2 and cos2theta+cos 2phi=3//2 , then cos^(2)(theta-phi)=