Beginner needs help with available fuctions in MathCAD

[kkärpuk]

Hey!

So i have two questions:

1) Is there a function in MathCAD that i can assign to a certain part of an equation so the program would take it into account ONLY if its value is positive.

As if when Mp(x) is negative, given the value of x, i would like MathCAD to only sum up the other two parts and leave out Mp(x).

2) I need to make a (x;y) graph, where the value of M(x) is always 0, but i dont' know how to. Is there a way?

In this equation, M(x) is bending moment in an arc thats shape is given with (x;y) coordinates. I need to graph the hypothetical shape of this arc, where bending moment equals 0 everywhere along the arc.
I also attached the .xmcd file, just in case.

English is not my first language so please tell me if i didn't make myself clear enough.

Thank you in advance!

[RichardJ · Accepted solution]

1) See the attached worksheet. The expression in parentheses is equal to 1 when Mp(x) is greater than or equal to zero, and equal to zero otherwise.

2) I think I'm missing something here, because surely that's just

[kkärpuk]

Thank you! As for my second question... guess overthinking got me good because this is exactly what i actually meant... awkward. I don't even know what i was looking for.

I appreciate your help!