how to know 'y' values of points when we only know 'x' values?

I know the coordinates of red points and slope of red line.

the black line is perpendicular to red line.

I know 'x' values(x1,x2)

but I don't know 'y' values, so I want to know 'y' values(y1,y2).

is there a fuction or a formular?

thanks

Answer 1

[AndresVar]

yes a perpendicular line has a negative inverse slope

so if red lines has slope m1=(dy/dx)_red, then the black line has slope m2=-1/m1=(dy/dx)_black