Solutions to $Delta u = u_xx + u_yy + u_zz = 0$ that only depend on r The 2019 Stack Overflow Developer Survey Results Are InProving that the bi-laplacian of a radial basis function is the dirac deltaLaplacian $Delta u$ in spherical coordinatesSolutions of the Laplace Equation in spherical coordinatesDoes particular+homogeneous capture all solutions for a linear pde?Laplacian in polar coordinates (idea)why is the laplacian of 1/r equal zero outside the origin?Laplace equation - boundary value problemApparent Contradictory Algebra in the Derivation of the Laplacian in Spherical CoordinatesSolve Laplace's equation in spherical coordinates, $nabla^2 u(r,theta,phi)=0$, in the general case.Deriving an Explicit Formula using Fundamental Solutions

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Solutions to $Delta u = u_xx + u_yy + u_zz = 0$ that only depend on r



The 2019 Stack Overflow Developer Survey Results Are InProving that the bi-laplacian of a radial basis function is the dirac deltaLaplacian $Delta u$ in spherical coordinatesSolutions of the Laplace Equation in spherical coordinatesDoes particular+homogeneous capture all solutions for a linear pde?Laplacian in polar coordinates (idea)why is the laplacian of 1/r equal zero outside the origin?Laplace equation - boundary value problemApparent Contradictory Algebra in the Derivation of the Laplacian in Spherical CoordinatesSolve Laplace's equation in spherical coordinates, $nabla^2 u(r,theta,phi)=0$, in the general case.Deriving an Explicit Formula using Fundamental Solutions










2












$begingroup$



Find all the solutions of $Delta u = u_xx + u_yy + u_zz = 0$ in
three dimensions that depend only on $r = 􏰃x^2 + y^2 + z^2$, the
radial variable in polar coordinates. Use the following formula for ∆
in spherical polar coordinates $$u_rr + frac2ru_r +
frac1r^2u_theta theta + frac1r^2cot(theta)u_theta +
frac1r^2 (sintheta)^2u_phi phi $$




I'm not sure how to start this problem. I'm thinking that $u_rr + frac2ru_r = 0$ if $u$ is only to depend on r? Not sure how to continue










share|cite|improve this question









$endgroup$







  • 1




    $begingroup$
    Yeah, that's how you start. If $u$ depends only on $r$, then $u_theta = u_phi = 0$. This is an ODE that you can solve a variety of ways.
    $endgroup$
    – Neal
    Apr 8 at 1:05















2












$begingroup$



Find all the solutions of $Delta u = u_xx + u_yy + u_zz = 0$ in
three dimensions that depend only on $r = 􏰃x^2 + y^2 + z^2$, the
radial variable in polar coordinates. Use the following formula for ∆
in spherical polar coordinates $$u_rr + frac2ru_r +
frac1r^2u_theta theta + frac1r^2cot(theta)u_theta +
frac1r^2 (sintheta)^2u_phi phi $$




I'm not sure how to start this problem. I'm thinking that $u_rr + frac2ru_r = 0$ if $u$ is only to depend on r? Not sure how to continue










share|cite|improve this question









$endgroup$







  • 1




    $begingroup$
    Yeah, that's how you start. If $u$ depends only on $r$, then $u_theta = u_phi = 0$. This is an ODE that you can solve a variety of ways.
    $endgroup$
    – Neal
    Apr 8 at 1:05













2












2








2





$begingroup$



Find all the solutions of $Delta u = u_xx + u_yy + u_zz = 0$ in
three dimensions that depend only on $r = 􏰃x^2 + y^2 + z^2$, the
radial variable in polar coordinates. Use the following formula for ∆
in spherical polar coordinates $$u_rr + frac2ru_r +
frac1r^2u_theta theta + frac1r^2cot(theta)u_theta +
frac1r^2 (sintheta)^2u_phi phi $$




I'm not sure how to start this problem. I'm thinking that $u_rr + frac2ru_r = 0$ if $u$ is only to depend on r? Not sure how to continue










share|cite|improve this question









$endgroup$





Find all the solutions of $Delta u = u_xx + u_yy + u_zz = 0$ in
three dimensions that depend only on $r = 􏰃x^2 + y^2 + z^2$, the
radial variable in polar coordinates. Use the following formula for ∆
in spherical polar coordinates $$u_rr + frac2ru_r +
frac1r^2u_theta theta + frac1r^2cot(theta)u_theta +
frac1r^2 (sintheta)^2u_phi phi $$




I'm not sure how to start this problem. I'm thinking that $u_rr + frac2ru_r = 0$ if $u$ is only to depend on r? Not sure how to continue







pde harmonic-functions laplacian






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Apr 8 at 0:53









meff11meff11

566




566







  • 1




    $begingroup$
    Yeah, that's how you start. If $u$ depends only on $r$, then $u_theta = u_phi = 0$. This is an ODE that you can solve a variety of ways.
    $endgroup$
    – Neal
    Apr 8 at 1:05












  • 1




    $begingroup$
    Yeah, that's how you start. If $u$ depends only on $r$, then $u_theta = u_phi = 0$. This is an ODE that you can solve a variety of ways.
    $endgroup$
    – Neal
    Apr 8 at 1:05







1




1




$begingroup$
Yeah, that's how you start. If $u$ depends only on $r$, then $u_theta = u_phi = 0$. This is an ODE that you can solve a variety of ways.
$endgroup$
– Neal
Apr 8 at 1:05




$begingroup$
Yeah, that's how you start. If $u$ depends only on $r$, then $u_theta = u_phi = 0$. This is an ODE that you can solve a variety of ways.
$endgroup$
– Neal
Apr 8 at 1:05










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