This is great - had tried something similar but didn't get the result. However, now I'm trying to replicate what you did to trace the line that goes from 38000 on x to the interception and i don't seem to be able too...
Well I'm simply trying to use the same kind of expression you created to also trace a vertical dotted line that goes from 38000 on the x axis to where the the blue and red lines cross. However it just doesn't work.
I've tried all of the following but they either give me an horizontal dotted line that goes from 0 to 38000 and overlaps the x axis or they give just one dot sitting on th ex axis at Quantity 38000.
=if(sum(K+ (v*Quantity))<=2280000 and Quantity=38000,38000)
=if([Costo totale]<=2280000 and Quantity=38000,38000)