.
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document.write( "Compute for the value of \r
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document.write( "~~~~~~~~~~~~~~~~~~~~~~ \r
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document.write( "1. Let me show first how to calculate more simple integral \r\n" );
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document.write( "
. (1)\r\n" );
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document.write( " Change variables for polar coordinates x =
, y =
.\r\n" );
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document.write( " Then dx*dy =
, and the integral (1) becomes \r\n" );
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document.write( "
=
= (introduce new variable z =
) =
.\r\n" );
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document.write( " The internal integral is \r\n" );
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\r\n" );
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=
=
| =
.\r\n" );
document.write( " |0\r\n" );
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document.write( " Then the entire double integral (1) is
=
.\r\n" );
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document.write( "2. Now, let us start with the original integral \r\n" );
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. (2)\r\n" );
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document.write( "To calculate this integral, let me introduce the new coordinate system \r\n" );
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document.write( " u = x,\r\n" );
document.write( " v =
.\r\n" );
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document.write( "Then\r\n" );
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document.write( " x = u, y =
; dx = du, dy =
, and the integral (2) becomes\r\n" );
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.\r\n" );
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document.write( " The integral of \"u\" and \"v\" after the factor
was just calculated in the section #1.\r\n" );
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document.write( " Hence, the final answer is
=
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\r
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document.write( "Answer. The integral (2) is equal to
.\r
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