Question

Which is the axis of symmetry of a parabola with equation y2=-8x? y = –2 y = 0 x = 0 x = 2

Answer 1

the axis of symmetry is y=0.

Answer 2

`y=0`

Explanation:

we know that

The equation in vertex form of a horizontal parabola is equal to

`x=(y-k)^(2) +h`

where

(h,k) is the vertex

and the axis of symmetry is the y -coordinate of the vertex

so

`y=k`

In this problem we have

`y^(2)=-8x` ----> is a horizontal parabola open to the left

The vertex is the origin

therefore

the equation of the axis of symmetry is equal to

`y=0`