A parabola is represented by the equation y squared is equal to 5 x Which equation represents the directrix?

The standard form of a parabola opening to the right is y² = 4px, where p is the distance from the vertex to the focus. Comparing y² = 5x with that form gives 4p = 5, so p = 5/4. The directrix is x = −p, which is x = −5/4, choice A.

AI-written and checked against the verified answer.