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Jun 5, 2022 at 15:14 comment added RobHarley asin3( a, b, c ) = intnum( th = 0, asin( b ), asin( a * sin( th ) * c / sqrt( cos( th )^2 - a^2 ) / sqrt( cos( th )^2 - c^2 ) ) );
Jun 5, 2022 at 14:38 comment added RobHarley Or use the change of variables beta = sin( theta ) for improved accuracy in edge cases.
Jun 5, 2022 at 14:37 comment added RobHarley asin3( a, b, c ) = intnum( be = 0, b, asin( a * be * c / sqrt( 1 - a^2 - be^2 ) / sqrt( 1 - be^2 - c^2 ) ) / sqrt( 1 - be^2 ) );
Jun 4, 2022 at 12:55 comment added user44143 @TMM, you are right. I will leave my comment up in case anyone else thinks the answer looks simple.
Jun 4, 2022 at 12:35 comment added TMM @MattF. No, it's not. The single-argument arcsin is a 1D integral, the 3-argument arcsin is a 1D integral over the single-argument one, and the 5-argument arcsin is a 1D integral over the 3-argument one. So it's a large number of 3D integrals which all need to be computed, which is probably still very hard to do accurately.
Jun 3, 2022 at 1:45 comment added user44143 @TMM, this is a conversion from a six-dimensional integral to one-dimensional integrals, so I think it does count as a simplification — indeed this answer would be easy to evaluate numerically while the original integral would not be.
May 4, 2022 at 2:23 comment added TMM And for what it's worth, the extra digits (assuming they are accurate) suggest there is no nice expression hidden there: wayback.cecm.sfu.ca/cgi-bin/isc/…
May 4, 2022 at 2:22 comment added TMM Thanks for the answer, but I'm not sure this simplifies anything - the original question involved an integral, and the answer now contains dozens of integrals that need to be evaluated. Maybe it helps with numerical evaluation of the result though.
May 3, 2022 at 16:43 history edited RobHarley CC BY-SA 4.0
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May 3, 2022 at 14:17 history edited RobHarley CC BY-SA 4.0
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May 3, 2022 at 7:37 comment added Alex M. While this answer one of the questions asked by the OP, it clearly is not enlightening. These computations look as if they were performed by a computer algebra system (which one?), so why not add the commands (program) that you used to produce them?
May 3, 2022 at 1:36 history edited RobHarley CC BY-SA 4.0
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May 3, 2022 at 1:32 review Late answers
May 3, 2022 at 2:11
S May 3, 2022 at 1:15 review First answers
May 3, 2022 at 7:37
S May 3, 2022 at 1:15 history answered RobHarley CC BY-SA 4.0