If sin x+sin y = a and cos x+cos y = b, find the values of: (i) tan (x+y/2) (ii) tan (x-y/2) Share with your friends Share 28 Anuradha Sharma answered this Given sinx+sin y = aSo 2sinx+y2cosx-y2=a......1and cosx+cos y = bSo 2cosx+y2cosx-y2=b......2dividing both the above equation we get, 2sinx+y2cosx-y2 2cosx+y2cosx-y2=abor tan x+y2=abNow squaring the two equation and adding we get, 4cos2x-y2sin2x+y2+cos2x+y2=a2+b24cos2x-y2×1=a2+b2cos x-y2=a2+b22=basehypotnuseNow tanx-y2=perpendicularbase=22-a2+b22a2+b2=4-a2-b2a2+b2 78 View Full Answer
