Focus and Directrix Worksheets

What Is the Focus and Directrix of Parabolas? Parabola is defined as the conic section formed by an intersection of the circular surface and a parallel plane, creating a straight line. The plane in parabola lies at the same angle as the exterior surface of the cone. In mathematical terms, a parabola is the set of all the points P lying a plane equidistant from a fixed line and a fixed point. All parabolas share some common features like an axis of symmetry, vertex, directrix, and focus. The point where the plane interacts with the exterior surface of the parabola is known as the vertex. In the figure shown above, the point present on the axis of the symmetry with the right angle is known as the focus. The straight-line present on the opposite side of the parabolic curve is known as the directrix. The parabolic curve represents the set of points lying equidistant from focus and directrix.