Help:For what $ alpha $ do the integrals exist?
Let
$ K_R (y) subset mathbb{R}^n $
be an n-dimensional Ball with radius $R>0$ and midpoint $y in mathbb{R}^n $
Far what $ alpha in mathbb{R} $ and $ n in mathbb{N}{0} $ do following integrals exist:
$ int_{K{_R(y)}} |x-y|^{alpha}dx $
$ int_{ mathbb{R}^n setminus K{_R(y)}} |x-y|^{alpha}dx $
$ int_{ mathbb{R}^n } |x-y|^{alpha}dx $
with what criteria can i solve this task?
I don't know how to begin.
Thanks for any help!!
Let's take
$ int_{K{_R(y)}} |x-y|^{alpha}dx $ ,$y=0, n=2 $
If I replace by polarcoordinates $ x= rsin phi $ :
$ int_0^{2 pi} int_0^R | r|^{alpha} r dr dphi $..is this the right way?
real-analysis integration multivariable-calculus
add a comment |
Let
$ K_R (y) subset mathbb{R}^n $
be an n-dimensional Ball with radius $R>0$ and midpoint $y in mathbb{R}^n $
Far what $ alpha in mathbb{R} $ and $ n in mathbb{N}{0} $ do following integrals exist:
$ int_{K{_R(y)}} |x-y|^{alpha}dx $
$ int_{ mathbb{R}^n setminus K{_R(y)}} |x-y|^{alpha}dx $
$ int_{ mathbb{R}^n } |x-y|^{alpha}dx $
with what criteria can i solve this task?
I don't know how to begin.
Thanks for any help!!
Let's take
$ int_{K{_R(y)}} |x-y|^{alpha}dx $ ,$y=0, n=2 $
If I replace by polarcoordinates $ x= rsin phi $ :
$ int_0^{2 pi} int_0^R | r|^{alpha} r dr dphi $..is this the right way?
real-analysis integration multivariable-calculus
Take $y=0$ and $n=2$ to start. You can use polar coordinates.
– zhw.
Nov 28 at 18:18
add a comment |
Let
$ K_R (y) subset mathbb{R}^n $
be an n-dimensional Ball with radius $R>0$ and midpoint $y in mathbb{R}^n $
Far what $ alpha in mathbb{R} $ and $ n in mathbb{N}{0} $ do following integrals exist:
$ int_{K{_R(y)}} |x-y|^{alpha}dx $
$ int_{ mathbb{R}^n setminus K{_R(y)}} |x-y|^{alpha}dx $
$ int_{ mathbb{R}^n } |x-y|^{alpha}dx $
with what criteria can i solve this task?
I don't know how to begin.
Thanks for any help!!
Let's take
$ int_{K{_R(y)}} |x-y|^{alpha}dx $ ,$y=0, n=2 $
If I replace by polarcoordinates $ x= rsin phi $ :
$ int_0^{2 pi} int_0^R | r|^{alpha} r dr dphi $..is this the right way?
real-analysis integration multivariable-calculus
Let
$ K_R (y) subset mathbb{R}^n $
be an n-dimensional Ball with radius $R>0$ and midpoint $y in mathbb{R}^n $
Far what $ alpha in mathbb{R} $ and $ n in mathbb{N}{0} $ do following integrals exist:
$ int_{K{_R(y)}} |x-y|^{alpha}dx $
$ int_{ mathbb{R}^n setminus K{_R(y)}} |x-y|^{alpha}dx $
$ int_{ mathbb{R}^n } |x-y|^{alpha}dx $
with what criteria can i solve this task?
I don't know how to begin.
Thanks for any help!!
Let's take
$ int_{K{_R(y)}} |x-y|^{alpha}dx $ ,$y=0, n=2 $
If I replace by polarcoordinates $ x= rsin phi $ :
$ int_0^{2 pi} int_0^R | r|^{alpha} r dr dphi $..is this the right way?
real-analysis integration multivariable-calculus
real-analysis integration multivariable-calculus
edited Nov 28 at 21:44
asked Nov 28 at 18:16
constant94
1415
1415
Take $y=0$ and $n=2$ to start. You can use polar coordinates.
– zhw.
Nov 28 at 18:18
add a comment |
Take $y=0$ and $n=2$ to start. You can use polar coordinates.
– zhw.
Nov 28 at 18:18
Take $y=0$ and $n=2$ to start. You can use polar coordinates.
– zhw.
Nov 28 at 18:18
Take $y=0$ and $n=2$ to start. You can use polar coordinates.
– zhw.
Nov 28 at 18:18
add a comment |
1 Answer
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Let $nomega_n$ denote the $n-1$ dimensional surface area of the $n-1$-sphere.
Your integrals, respectively, are
$$int_{K_R(y)} |x-y|^alpha , dx= int_0^R int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^R |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n setminus K_R(y)} |x-y|^alpha , dx= int_R^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_R^infty |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n} |x-y|^alpha , dx= int_0^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^infty|x-y|^{n+alpha} , dr$$
where $dx$ is the usual $n$-dimensional volume element in the integrals on the left and the $n-1$ dimensional surface area element in the integrals in the middle.
The remaining improper integrals are straight forward to work out.
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Let $nomega_n$ denote the $n-1$ dimensional surface area of the $n-1$-sphere.
Your integrals, respectively, are
$$int_{K_R(y)} |x-y|^alpha , dx= int_0^R int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^R |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n setminus K_R(y)} |x-y|^alpha , dx= int_R^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_R^infty |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n} |x-y|^alpha , dx= int_0^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^infty|x-y|^{n+alpha} , dr$$
where $dx$ is the usual $n$-dimensional volume element in the integrals on the left and the $n-1$ dimensional surface area element in the integrals in the middle.
The remaining improper integrals are straight forward to work out.
add a comment |
Let $nomega_n$ denote the $n-1$ dimensional surface area of the $n-1$-sphere.
Your integrals, respectively, are
$$int_{K_R(y)} |x-y|^alpha , dx= int_0^R int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^R |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n setminus K_R(y)} |x-y|^alpha , dx= int_R^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_R^infty |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n} |x-y|^alpha , dx= int_0^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^infty|x-y|^{n+alpha} , dr$$
where $dx$ is the usual $n$-dimensional volume element in the integrals on the left and the $n-1$ dimensional surface area element in the integrals in the middle.
The remaining improper integrals are straight forward to work out.
add a comment |
Let $nomega_n$ denote the $n-1$ dimensional surface area of the $n-1$-sphere.
Your integrals, respectively, are
$$int_{K_R(y)} |x-y|^alpha , dx= int_0^R int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^R |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n setminus K_R(y)} |x-y|^alpha , dx= int_R^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_R^infty |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n} |x-y|^alpha , dx= int_0^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^infty|x-y|^{n+alpha} , dr$$
where $dx$ is the usual $n$-dimensional volume element in the integrals on the left and the $n-1$ dimensional surface area element in the integrals in the middle.
The remaining improper integrals are straight forward to work out.
Let $nomega_n$ denote the $n-1$ dimensional surface area of the $n-1$-sphere.
Your integrals, respectively, are
$$int_{K_R(y)} |x-y|^alpha , dx= int_0^R int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^R |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n setminus K_R(y)} |x-y|^alpha , dx= int_R^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_R^infty |x-y|^{n+alpha} , dr$$
$$int_{mathbb R^n} |x-y|^alpha , dx= int_0^infty int_{|x-y| = r} |x-y|^alpha , dx , dr = n omega_n int_0^infty|x-y|^{n+alpha} , dr$$
where $dx$ is the usual $n$-dimensional volume element in the integrals on the left and the $n-1$ dimensional surface area element in the integrals in the middle.
The remaining improper integrals are straight forward to work out.
answered Nov 28 at 21:52
Umberto P.
38.3k13063
38.3k13063
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add a comment |
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Take $y=0$ and $n=2$ to start. You can use polar coordinates.
– zhw.
Nov 28 at 18:18