Changing the integration order

1 Analysis: Questions

  1. (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
  2. (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.
  3. 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.
  4. (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!
  5. 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).
  6. 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