(3) Define g(z) - Inr+i0 <00 and (i) Sketch the domain D of the function g(z) and show that g(z) is analytic on this domain and find

g'(z). (ii) Show that the composite function G(z) = g(2²+1) is analytic on the half-plane H = {z=z+iy : x>0}, with derivative 2z 2² +1 G(z)= (4) (i) Define what it means for a subset of C to be open. (ii) Define what it means for a subset of C to be a domain. (iii) Suppose f(2)= u(x, y) +iu(x, y), z=1+iy, x,y ER, for z in a domain D. Prove that if f is analytic on this domain D then f'(2)=0 for all z in D, and hence f is constant on D.