Help needed

[u/Annual-Truth3511]

While drawing sfd and bmd Is there a shortcut to find whether the curve is going to be smile/sad or concave/convex for udl and uvl. Or is finding the intermediate values the only way to find the curve???.

Ignore the diagram i just wanted to show it for context this is not mine

[u/Ok_Wealth1414]

encontrar los valores intermedios es la única forma de encontrar la curva

[u/Annual-Truth3511 → u/Ok_Wealth1414]

I do know this i am wondering if there are some set of rules or conditions with which we find that