A student observes the two points A(0,4) and B(0,−2) and claims that the line passing through them is horizontal.
(i) Determine whether the line through A and B is vertical or horizontal. Give a brief reason for your answer.
(ii) Write the equation of the line passing through A and B.
(iii) Explain how the constant term in the equation obtained in part (ii) helps you identify the orientation of the line.