On Monday, 30 June 2014 21:36:18 UTC+1, pauland...@gmail.com  wrote:   
   > On Monday, 30 June 2014 20:22:55 UTC+1, Axel Vogt  wrote:   
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   > > On 30.06.2014 20:01, paulandrewbird@gmail.com wrote:   
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   > > > integral( exp( a*x^4+4*b*x^3*y+6*c*x^2*y^2+4*d*x*y^3+e*y^4)   
   ,x=-infty..infty, y=-infty..finty)   
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   > > > I'm guessing it's going to be in the form 1/P(a,b,c,d,e)^(1/8) where P   
   is a 4th degree polynomial in the coefficients of the quartic.   
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   > > > My guess is that P is the discriminant of the polynomial but that is   
   just a guess.   
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   > > what do you get and expect if integrand = exp(+-x^2*y^2) ?   
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   > Well that would be pi.   
      
   Sorry no I was thinking of exp(-x^2-y^2). I'm not sure your example converges.   
   What's your point?   
      
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