If f (z) = u(x, y) + i.v (x, y) be analytic everywhere and u – v = (x – y).(x2 + 4xy + y2), then-
1
f (z) = z (1 – i.z) + c, c is arbitrary constant
2
f(z) = z2 (1 + i) + c, c is arbitrary constant
3
f(z) = – i.z3 + c. c is arbitrary constant
4
f(z) = i.z3 + c, where c is arbitrary constant