Question

Which way does the parabola open​

Answer 1

D. Down

Explanation:

The given equation is

`y=ax^2`

This is a parabola whose axis of symmetry is the y-axis.

If
`a` is negative, the parabola opens down.

If
`a` is positive, the parabola opens up.

Answer 2

our parabola open downward and therefore a is negative

Explanation:

As value of a changes from positive to negative or from negative to positive, the direction of opening changes. For negative values of a we got negative parabolas that open downward. As the original formula y = x^2 we see that x^2 will always be positive because when you square a number it always gives positive value. Therefore the direction for which it will open, depends on value of a.