[Maxima-bugs] [ maxima-Bugs-1714044 ] Maxima asks unnecessary questions in integration

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Bugs item #1714044, was opened at 2007-05-07 01:21
Message generated for change (Comment added) made by rtoy
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Category: Lisp Core - Integration
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Robert Dodier (robert_dodier)
Assigned to: Nobody/Anonymous (nobody)
Summary: Maxima asks unnecessary questions in integration

Initial Comment:
Following example shows Maxima asking a lot of questions, although the result doesn't depend on the answers; I consider that a bug.

This is from the mailing list 2007-04-13, "integration asks to many questions".

(%i1) p:(1+a*cos(kp*x1)+a*cos(kp*x2)+a*a*cos(kp*x1)*cos(kp*x2))*sin(kp*(x1-x2)/4);
(%i2) p2:p*(1+c*cos(kp*(x1+x2)/2));
(%i3) integrate(integrate(p2^2,x1,-4*%pi/kp,4*%pi/kp),x2,5*%pi/kp/2,7*%
pi/kp/2);

Is  kp  positive or negative?
p;
Is  a  zero or nonzero?
n;
Is  a c  positive, negative, or zero?
n;
Is  c  zero or nonzero?
n;
Is  a  positive or negative?
n;
Is  c  positive or negative?
p;
Is  cos(kp x2)  positive, negative, or zero?
p;
Is  kp  positive or negative?
p;

<result here>

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>Comment By: Raymond Toy (rtoy)
Date: 2007-06-13 15:01

Message:
Logged In: YES 
user_id=28849
Originator: NO

FWIW, the maxima is computing this integral via method-radical-poly.  It
can find the antiderivative and is now carefully substituting the limits in
via intsubs.  Since the antiderivative only involves trig functions (no
inverses), there shouldn't be a problem just substituting in the limits.  

Perhaps easy-subs needs to be extended to handle this case?


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Comment By: Nobody/Anonymous (nobody)
Date: 2007-06-12 23:18

Message:
Logged In: NO 

I had the same silly question  when integrating
exp(ïky)*hermite(n,x)*x^j

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