Triple Integral

[parisse]

I don't think so:

Code:


t1 := 4*x^2*ln(sqrt(-x^2+4)+2) - x^4*ln(abs(x));
t2 := -x^2*sqrt(-x^2+4) - x^4*ln(x^2)/4 + x^4*ln(abs(x^2+4*sqrt(-x^2+4)-8))/4;
int(t1-t2, x=-2.0..2.0) ;
int(t1-t2,x=-2..2)*1.0;

If you plot(t1-t2,x=-2..2) the value of about 28 is credible.
BTW, 1.4.9 is relatively old, if you want to report bugs in Xcas, please check with the latest version :-)

I have improved embedded assumptions checking for some simplifications, now the initial triple integral returns the correct exact value.