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    Elliptic Boundary Value Problem: Lapalce and Polar Coordinates

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    (lap) means the Laplacian
    Vrr means the second derivative of V with respect to r
    V(theta theta) means the second derivative of V with respect to theta

    Solve:
    (lap)V(r,theta)= Vrr+(1/r)Vr+(1/r^2)V(theta theta)=0
    0 < r < 1, -(pi) < theta < pi

    V(1,theta) = {1, -(pi/2) < theta < (pi/2)
    {0, elsewhere

    Please show all work including the derivation of any eigenvalues or eigenvectors.
    Thank you

    © BrainMass Inc. brainmass.com October 9, 2019, 3:42 pm ad1c9bdddf
    https://brainmass.com/math/numerical-analysis/elliptic-boundary-value-problem-laplace-polar-coordinates-10845

    Solution Preview

    Please see the attached doc file.

    We have:

    We consider:

    Therefore by substitution we have:

    and we can simplify as:

    This must be a constant. The constant can be positive, negative or zero. In these kinds of problem, the positive choice works. We call that k^2. Then:

    k must be a whole number according ...

    Solution Summary

    This shows how to solve an elliptic boundary value problem with Laplace and polar coordinates. The means for the second derivative with respect to theta are given.

    $2.19