To solve this problem you must keep on mind the following information: By definition, a quadratic function has the following form:
[tex] y=ax^{2}+bx+c
[/tex]
Where [tex]a
[/tex] is the leading coefficient.
If the leading coeficient is closer to zero, the parabola is widest,if it has a larger positive or negative value, the parabola is narrowest.
Therefore, by knowing the information above, you have that the answer is:
[tex]y=- x^{2} \\ y=-4.5 x^{2} \\ y=6 x^{2} [/tex]
