Which of the quadratic functions has the narrowest graph? 1)y=9x^2 2)y=-0.9x^2 3)y=-10x^2 4)y=2/5x^2

3) y=-10x^2
The quicker the graph moves up (or down in this case), the more narrow it will be. + and - values of x^2 only tell you whether it's a positive quadratic (U-shape) or a negative one (umbrella). So the larger the
| coefficient | of x^2 then the more narrow it will be, and likewise the smaller it is such as a fraction, the wider it will become