If `sinA=sinB` and `cosA=cosB`, then prove that `sin. (A-B)/(2)=0`.

If sinA=sinBand cosA=cosB , then prove that " sin "(A-B)/(2)=0 .

If sinA+sinB=a and cosA+cosB=b,then cos(A+B)

If sinA+sinB=a and cosA+cosB=b,then cos(A+B)

If sinA = sinB and cosA = cosB then prove that, either A=B or they differ by multiples of four right angles.

If sinA+sinB=a and cosA+cosB=b, show that sin(A+B) = (2ab)/(b^2+a^2)

If sinA+sinB=l and cosA-cosA-cosB=m , then cos(A-B)=

If sinA+sinB=c,cosA+cosB=D, then the value of sin(A+B)=

If sinA+sinB=C,cosA+cosB=D , then the value of sin(A+B) =