Question

If S = {z ∈ c : 1 ≤ |z - (1 + i) ≤ 2) and A = {z ∈ s: |z - (1 - i) = 1} then A is 

(1) null set

(2) singleton set

(3) exactly two element

(4) infinite elements

Answer 1

Set A contains all points on minor are AB of circle |z - (1 - i)| = 1