A point P(5,6) lies on a parabola whose equation is of the form y2=4ax.
(i) Verify that P satisfies an equation of this form and hence find the value of a.
(ii) For this value of a, determine the coordinates of the focus and the equation of the directrix.
(iii) Plot at least three suitable points (including P and its reflection in the x-axis) and sketch the corresponding parabola, indicating clearly its orientation.