The point of the form (a, a), where a ≠ 0 lies on
When a = 1 then we get the point (1,1)
When a = 2 then we get the point (2,2)
When a = 3 then we get the point (3,3)
And so on
On plotting these points on the graph we will get the equation of liney = x
⇒ y – x = 0