How to plot a value of a curve of a certain point

Hello,

Do you know if it is possible to plot a value of y for a given input value x? To make it little bit more clear… in order to plot the p1w1c1.x,y maximum / minimum value you call max(p1w1c1.y) or min(p1w1c1.y) but if you want to calculate-plot an y value for a given x value? Is it possible?

Thank you in advance