in triangle ABC, if angle C= pi/2, then prove that sin (A+B)= a2-b2/a2+b2 Share with your friends Share 1 Anuradha Sharma answered this Hi, taking RHS, a2-b2a2+b2= k2sin2A-k2sin2Bk2sin2A+k2sin2B using sine rule asinA=bsinB=csinC=k= sin2A-sin2Bsin2A+sin2Bsince C = 90 so A+B= 90 sin2A+sin2B= sin2A+sin290-A= sin2A+cos2A= 1 sin2A-sin2Bsin2A+sin2B=sin2A-sin2B=sin2A-cos2A= -cos2ABut nowhere we are getting RHS as sinA+Bso please recheck the question. Regards -9 View Full Answer