Question: Problem with elliptic integrals and assuming

Hi there

There seems to be a bug when evaluating elliptic integrals using assuming. Here's an example:



is our integral for some a. Now evaluate the integral using assuming on X in different ways:


INT2:=simplify(value(INT)) assuming X>0, a>0, a<1;

INT3:=simplify(value(INT)) assuming X<0, a>0, a<1;


These give analytic solutions which are different. Now plot them both and compare to the numeric solution




I'm finding that the red curve which should work for X>0 is wrong, while the green one which is for X<0 is ok for X either sign. [blue is the correct answer - numerically!]


Any ideas?

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