1 Analysis: Questions
- (a) Calculate
Z 1
0
Z 1
0
sin (e
x
) dx
dy +
Z e
1
Z 1
ln y
sin (e
x
) dx
dy.
Tip: Drawing the integration area and changing the integration order can be
an opportunity to attack the problem.
(b) Calculate the volume of the body
K =
(x, y, z) : x
2 + y
2 + z
2 ≤ 12, z ≤ 1, x + y > 0 - (a) Formulate Stokes’s theorem with all predictions.
(b) Verify your Stoke’s theorem for the vector field F(x, y, z) = (z
2
, x2
, y2
)
and the area Y given by
(x − z)
2 + (y + z)
2 = z
2
for 0 ≤ z ≤ 1.
That is, calculate the curve integral R
(∂ Y ) F.dr both directly and with the help of
Stokes’s theorem. Your solution should clearly state how you choose orientation. - Betrakta
Z
Γ
x + y
x
2 + y
2
dx +
−x + y
x
2 + y
2
dy.
(a) Calculate the curve integral, where the curve Γ goes in the half-plane y ≥ 0
from the point (1, 0) to (−1, 0) along the superellipse x
6 + 3y
6 = 1.
(b) List all the statements you have used in (a) and explain how.
Note: If in the formulation of the statement, e.g. a field F, then indicate
how you have chosen F in the example,and explain why all the set of prerequisites are met.
(c) Enter a curve Γ such that the curve integral becomes zero and justify your
choice. - (a) Consider the series
X∞
n=0
2n
n
z
n
. (1)
i. Determine the radius of convergence of the series.
ii. Enter an amount of M ⊂ C such that the series converges uniformly in
M.
iii. The new concepts of uniform convergent function sequence and uniform
convergent function series. Explain the difference between point-by-point and
uniform convergence pursuits.
(b) Consider the series
X∞
n=1
(−1)n
n · 9
n
z
2n
.
1
i. Determine the radius of convergence of the series R.
ii. Determine the value of the series for |z| < R.
iii. Does the series also converge for all z C with |z| = R?
Motivate your answers! - Let f be a complex value function in an open subset of the complex speech
plane C.
(a) Enter the definition of an analytical function.
(b) State two properties of f that are equivalent to the analytical property.
(c) Determine all real-value analytical functions f in C, that is, determine all
analytical functions f(z) = u(x, y) + iv(x, y) with imaginary part v(x; y) = 0
for all x and y (where as usual z = x + iy). - Let f be a function that is analytic in an open quantity containing the
closed unit circle disk D = {z C; |z| ≤ 1} .
Show: If |f (x)| ≤ 1 for all z with |z| = 1, then |f (0)| ≤ 1 also applies.
Tip: Cauchy’s integral formula and the triangle probability of integrals can be
helpful.
Sample Solution