The answer for the first one is $a$ as it should be. However, for the second one I get $|\sin(\theta)|$. Considering that I have already assumed $0<\theta<\pi$, I should not have got the absolute sign. Is this a bug? And is there a way to get around it?
Maxima 5.22.1 http://maxima.sourceforge.net
using Lisp ECL 10.4.1
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%o1) [theta > 0]
(%o2) [theta < %pi]
Quoted here: "Maxima's deduction mechanism is not very strong; there are many obvious consequences which cannot be determined by is. This is a known weakness."