Question

Let u = (2z + i)/(z - ki), z = x + iy and k > 0. If the curve represented by Re(u) + Im(u) = 1 intersects the y-axis at the points P and Q where PQ = 5, then the value of k is :

(1) 3/2 

(2) 4 

(3) 2 

(4) 1/2

Answer 1

Answer is (3) 2