- #1
Bashyboy
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Homework Statement
Suppose we have the function ##f(z) = x + iy^2## and a contour given by ##z(t) = e^t + it## on ##a \le t \le b##.
Find ##x(t)##, ##y(t)##, and ##f(z(t))##.
Homework Equations
The Attempt at a Solution
Well, ##x(t)## and ##y(t)## are rather simple to identity. However, I am having difficulty determining ##f(z(t))##, which I believe seems from some notational issues.
##f(z) = f(z(t)) = f(\underbrace{e^t + it}_?) = ...?##
I could write
##f(z) = x + iy^2 \iff##
##f\langle (x,y) \rangle = x + iy^2##.
I know that ##x(t) = e^t## and ##y(t) = t##.
##f\langle (x(t), y(t) ) \rangle = x(t) + i[y(t)]^2 \iff##
##f\langle (x(t), y(t) ) \rangle = e^t + it^2##.
I find this somewhat unsettling. Suppose that I have the function ##f(z) = f(x,y) = u(x,y) + iv(x,y)## (I am dropping the ##\langle \rangle## notation); and suppose that we have the contour described by the parametric function ##z(t) = x(t) + iy(t)##. In the general case, would the composition look like
##f(x(t),y(t)) = u(x(t),y(t)) + iv(x(t),y(t))##?
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