What is the order, from narrowest to widest graph, of the quadratic functions f (x) = - 10x², f (x) = 2x², f (x) = 0.5x²?

The equations given among the choices projects a parabola with different lengths of latus rectum. This means to determine which graph projects the narrowest and the widest among all, we compare the absolute value of the coefficient before x2. The narrowest is the smallest hence f (x) = 0.5x2 and the widest is f (x) = - 10x²