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

Answer 1

in y = ax^2
as |a| get bigger, the parabola become more narrow, and conversely,
as |a| gets smaller, the parabola becomes more open or wide.

so in your case, y = -10x^2 is the most narrow, the negative merely
shows that the parabola opens downwards