It has been discussed here quite some times that Mathcad is not able to produce publication quality plots.
The edges I see in your plots are due to screen resolution only, I guess. I don't think that they result from calculation inaccuracies in your function - in some rare cases special (pathologic?) function will produce tiny steps as of numeric inaccuracy. Use mathcads zoom ability (right click, zoom) and judge yourself.
Sometimes you get better optical results by increasing the linewidth. You may also consider enlarging the graph area before you copy it to the clipboard, but be careful with that, as this would probably mean that you have to reduce the image size in Wod und that way the label font size will be smaller at the inserted graph and this will look inconsistent unless you do it likewise with all of the graphs in your paper..
Anyway, I guess Mathcad's smoothing routines are not meant to do and will not do that kind of antialiasing you have in mind. There is no reason to use that kind of smooth Mathcads routines will provide on a graph, which is defined by an analytic function.