A directrix is a fixed line used in the definition and construction of conic sections, which helps determine the shape and properties of these curves. It is essential in defining parabolas, ellipses, and hyperbolas, as it relates to the focus of these shapes. The distance between any point on the conic section and the focus is measured in relation to the distance to the directrix, establishing a geometric relationship that characterizes each conic type.
congrats on reading the definition of directrix. now let's actually learn it.