Order the group of quadratic functions from widest to narrowest graph. y=-7x^2, y=-1/5x^2, y=-1/3x^2

When plotted in a x-y plot, the widest quadratic function is y = - 7x^2. The general equation for a parabola is y = 4ax^2. All functions opens downward. The value of a for each function is:

y = - 7x^2 : a = - 7/4

y = - 1/5 x^2 : a = - 1/20

y = - 1/3 x^2 : a = - 1/12

The function with the highest value of a is the widest and the lowest value of a is the narrowest.