Difficulty with 2D plotting

[supersonic]

I'm having some difficulty making a simple 2D plot.  Deleting all units permits this to be plotted, but I can't find the error when I do have units introduced.  I tried making a range variable, with no success.  I bet someone can take a glance at this and point out what I've done wrong pretty quickly. 

[ValeryOchkov · Accepted solution]

Do please before the graph plotting

x := 1 in, 1.01 in..10 in

for example!

And send please the Mathcad file!