> (%i6) nintegrate(1/sqrt(x), x, -1, 1); > (%o6) nintegrate(1/sqrt(x),x,-1,1) <-- hides a division by zero error I wanted to say (%i3) nintegrate(1/sqrt(abs(x)), x, -1, 1); (%o3) nintegrate(1/sqrt(abs(x)),x,-1,1) <-- hides a division by zero error here. -- Andrej