The correct option is B 2(1+m1)(1+m3)=(1+m2)(2+m1+m3)
Substituting y=mx in x+y=1 we get x+mx=1→x=11+m→y=m1+m
So Co-ordinates of A,B,C are (11+m1,m11+m1)(11+m2,m21+m2)(11+m3,m31+m3) respectively
Since AB=BC
B is midpoint of AC and lies ony=m2x
∴12×(m11+m1+m31+m3)=m2×12×(11+m1+11+m3)
On solving, we get
2(1+m1)(1+m3)=(1+m2)(2+m1+m3)