[i]Farhan participates in a cycling event organized by a cycling society. Farhan is cycling along a straight road. At t hours after passing the starting point, its acceleration, a [math]kmh^{-2}[/math], is given by [math]a=4t-16[/math] and his starting velocity is -18 [math]kmh^{-1}[/math][/i][br][br][i](a) Express the displacement function, s, and the velocity function, v, in terms of t[/i]

[i](b) Prove that Farhan stops for a moment at t = 3[/i]

[i](c) Find the total distance, in km, covered by Farhan in the first 3 hours.[/i]