The <em>correct answer</em> is:
f(x) = -10x², f(x) = 2x², and f(x) = 0.5x²
Explanation:
For a quadratic in standard form, f(x) = ax²+bx+c, the value of a describes the width and direction of the parabola. If a is positive, the parabola is open upward. If a is negative, the parabola is open downward.
If a < 1, a fraction or decimal, the graph is wider than the parent function f(x)=x². If a > 1, the graph is narrower than the parent function f(x)=x². The larger the value of a is (a > 1), the narrower the graph is. This makes the function with the decimal value of a the widest; the remaining graphs are in order of the value of a, least to greatest.