Prove the following statements using any method

We say that a point P = (x, y) in R 2 is rational if both x and y are rational. More precisely, P is rational if P = (x, y) Q 2 . An equation F(x, y) = 0 is said to have a rational point if there exists x0, y0 Q such that F(x0, y0) = 0. For example, the curve x 2 + y 2 1 = 0 has rational point (x0, y0) = (1,0). Show that the curve x 2 + y 2 3 = 0 has no rational points.