Dear Master



>>>>> "maryam" == maryam shamssolary <shamssolary at gmail.com> writes:

    maryam> Dear Master


    maryam> I am a young researcher in numerical linear algebra. For some calculations, I used your "Maxima"
    maryam> software. But I have some problems with some commands such as:
    maryam> ?integrate(1/(r+s*x+t*x^2)*1/sqrt(1-x^2), x, -1, 1);


    maryam> give me this message:?
    maryam> "Is? "4*r*t-s^2"? positive, negative, or zero?"


    maryam> I tried different answers but did not?! What do you suggest?

Maxima cannot do all integrals of this form. It appears that maxima
can only do this if t*x^2+s*x+r has real roots. The case for complex
roots is not handled. This is why maxima is asking for the sign of
4*r*t-s^2. The roots are real if 4*r*t-s^2 is zero or negative.

After this maxima may ask many more questions as it breaks the
original integral into two new integrals. I find the questions hard to
answer. :-(

You might get a feel for what is going on by using some numerical
values for r, s, and t.

Sorry that maxima can't easily produce an answer for you.

Ray