Ive added a second equation therefore a 2nd graph. After yuo plot the graph you can find the intercept of the 2 graphs. This took a lot of a shorter time to make and i happy about that. It shoes that im getting more accustomed to tkinter and programming in general. Also i think the code to find the intercpet is pretty neat so im going to paste it in  for pixel_x in range(450):        x = (pixel_x - 450/2) / k        try:            y1 = eval(rovnica1)            y2 = eval(rovnica2)            rozdiel = abs(y1-y2)            if rozdiel < najmensi_rozdiel:                najmensi_rozdiel = rozdiel                priesecnik_x = pixel_x                priesecnik_y = 225 - (y1 * k)        except:            continue