QUESTION 1 [21)
1.1. Express~
-
1
~i
in
the
form
of x
+ iy,
where
x, y
E
IRL
[6]
1-1
I
= 1.2. Find the principal argument of the complex number given by z (l~~) 2 •
[6]
G 1.3. Compute cos + i).
[9]
QUESTION 2 [9]
Let lz+ 11= lz- ii be a curve in the complex plane. Then
2.1. describe the type of curve represented by lz+ 11= lz- ii.
[6]
2.2. determine whether the curve is open or closed, connected or unconnected, bounded or
unbounded. Justify your answer.
[3]
QUESTION 3 [9]
Find cos 48 and sin 48 in terms of sin 8 and cos 8.
[9]
QUESTION 4 [25)
x3-y3+i(x3+y3)
* if Z 0
Let f(z) = {
x2+y 2
0 if z = 0
. Then show that
4.1. Cauchy-Riemann Equations are satisfied at (0, 0).
[15]
4.2. f' (0, 0) does not exist.
[10]
QUESTION 5 [14)
Let f: IR2 IR be twice differentiable function.
5.1. What does it mean to say f is harmonic?
[2]
5.2. Determine whether u(x, y) = 2x - x 3 + 3xy 2 is harmonic or not. If it is harmonic find
= its harmonic conjugate function v(x, y) such that f(z) u(x, y) + iv(x, y) is analytic. [12]
2