Question

Determine whether each parabola has a horizizontal or vertical directrix

Answer 1

we know that

A vertical parabola of the form

y=a(x-h)^2+k has a vertical directrix (x=h)

and a horizontal parabola of the form

x=a(y-k)^2+h has a horizontal parabola (y=k)

therefore

In this problem

option 1 ----> horizontal directrix

option 2 -> horizontal directrix

option 3 ---> vertical directrix

option 4 -> vertical directrix