@Kitonum I meant that even along the y-axis we have the set of integers, not the set of real numbers as in the usual case.

When a polynomial is fitted through the three points as we can see even in the graph the curve is present even int he range between 2 and 3 and also between 3 and 4 etc. Does that mean that the curve is present for even the points between 2 and 3 and etc.? Doesn't it create a problem when we are considering only the integers?

Thank you very much.