For part c) The equation of ON is y = -0.5x which is correct; i know to solve it i need to find the integral between the limits 5/2 and 0 of the area of the curve - the area of the line, but what i dont understand is why that is. If I take the integral of the limits 2 and 0 of the curve, which area i'm i actually finding? It seems like im doing things without understanding them, could someone show me a sketch? Also, if i'm finding the integral of the line y = -0.5x of the limits 5/2 and 0, which area am i exactly finding? Why is it the integral between the two equations which is the shaded bit? If anyone could clear this up would be great.