This bug is marked as solved > * 1044318: defint(1/(sin(x)^2+1),x,0,3*%pi) wrong Indeed defint(1/(sin(x)^2+1),x,0,3*%pi) give the right answer -> 3 sqrt(2) pi/2. however defint(1/(a^2*sin(x)^2+1),x,0,3*%pi) still gives 0