Let a, b, x and y be real numbers such that a−b=1 and y≠0. If the complex numbers z=x+iy satisfies Im (az+bz+1)=y, then which of the following is/are possible value(s) of x?
−1−√1−y2
−1+√1−y2
az+bz+1=ax+b+aiy(x+1)+iy=(ax+b+aiy)((x+1)−iy)(x+1)2+y2∴Im(ax+bz+1)=−(ax+b)y+ay(x+1)(x+1)2+y2⇒(a−b)y(x+1)2+y2=y∵a−b=1∴(x+1)2+y2=1∴x=−1±√1−y2