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 KiB) downloaded 73 time(s).

... 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 KiB) downloaded 61 time(s).