Q:
# What is the directrix of a parabola?

**The directrix of a parabola refers to a straight line that is drawn perpendicular to the axis of symmetry of a parabola.** This line does not touch the parabola at any point. In addition, it is a horizontal line if the axis is vertical.

To draw a parabola, one has to start with the directrix and a point, known as focus that is off to one side. The parabola, which is the curve, is then formed from all points that are equidistant from the focus and the directrix. The axis of symmetry is a perpendicular line to the directrix that splits the parabola in the middle and passes through the focus.

Learn more about Geometry-
Q:
## What is vertex form?

A: The vertex form of a quadratic equation is written like f (x) = a(x - h)2 + k, with the letter h and the letter k being the vertex point of the parabola. I... Full Answer >Filed Under: -
Q:
## How many edges does a cylinder have?

A: A cylinder technically has two curved edges, but in mathematics, an edge is defined as a straight line. Therefore, a cylinder actually has no edges, no ver... Full Answer >Filed Under: -
Q:
## What is a chord in math?

A: A chord is a straight line that connects two points on the curve of a circle. Unlike a secant, which is a line that extends infinitely in both directions, ... Full Answer >Filed Under: -
Q:
## What is a ray in geometry?

A: In geometry, a ray is a straight line extending infinitely from a fixed point. A ray is expressed using an arrow as its symbol (---). A ray cannot be measu... Full Answer >Filed Under: