Question

Order the group of quadratic functions from widest to narrowest graph. y=-4x^2, y=-3x^2, y=-5x^2

Answer 1

I think it should be y=-3x^2,y=-4x^2,y=-5x^2

Answer 2

wider means that if you move some units down in y, which graph will have more distance between it's x's at that y.

take at y=-1 for y=-ax^2, calculate x's at y=-1. gives x= +- 1/sqrt(a) or
width=2/sqrt(a)

So a larger 'a' means narrower

Answer 3

thanks guys