The region of argand plane defined by |z+1|+|z-1|≤4 is
Interior and boundary of ellipse
As |z- a| + |z + a| = 2b
represents set of z, sum of whose distances from (a,0) and (-a,0) is 2b and it will be an ellipse if 2a < 2b. In the question a = 1 and b = 2,
∴2a<2b
Hence |z - 1| + |z + 1| ≤ 4