
“ca: ch_02” — 2012/3/27 — 19:14 — page 43 — #3
Analytic Functions
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then point P
(w) will move along a corresponding curve C
in the w-plane since to each point
z =(x, y), there corresponds a point w =(u, v). We say that the function w = f (z) thus defines a
mapping or transformation of the z-plane into the w-plane and the curve C in the z-plane is mapped or
transformed into the curve C
into the w-plane by transformation. We call P
(w) the image of P(z), i.e.
the image of a point z in the domain of definition S is the point w = f (z). If M ⊆S, then the set of image
of all points in the set M is the image of M. The set R ={f (z) : z ∈ S} of the image ...