This difficult Frechet is like encountering an albinos Elephant walking on high pink heels.
Smath plots nicely ... Mathcad => zap !

Integral 00000000000 Frechet Bug.sm (117,34 KiB) scaricato 1401 volta(e).

... doctored in two ways.
Native integrator hides a silent bug, in fact miss-coded as it appears.
The complex result is more than a bug.
Otherwise: native integrator ranges from exact to good for bell shapes.



Integral 00000000000 Frechet Bug.sm (142,1 KiB) scaricato 1329 volta(e).