Definition of directrix in English:
directrix
nounPlural directrices dʌɪˈrɛktrɪksdɪˈrɛktrɪksdəˈrɛktrɪks
Geometry A fixed line used in describing a curve or surface.
Example sentencesExamples
- In the following, the feet of perpendiculars dropped from points A, B, etc. on the parabola to the directrix will be denoted A ’, B ’, etc.
- It is the pedal curve of the parabola where the pedal-point is taken as the reflection of the focus in the directrix.
- The directrix is used in the construction, which follows, mutatis mutandis, the same course as the above construction in the case of the ellipse.
- The hyperboloid is then indented and connected to a series of hyperbolic paraboloids through their common directrices, thereby leading the ensemble toward the four load-bearing points to the ground.
- The focus and directrix of a hyperbola were considered by Pappus.
Origin
Early 18th century: from medieval Latin, literally 'directress', based on Latin dirigere 'to guide'.
Definition of directrix in US English:
directrix
noundəˈrɛktrɪksdəˈrektriks
Geometry A fixed line used in describing a curve or surface.
Example sentencesExamples
- The directrix is used in the construction, which follows, mutatis mutandis, the same course as the above construction in the case of the ellipse.
- It is the pedal curve of the parabola where the pedal-point is taken as the reflection of the focus in the directrix.
- The hyperboloid is then indented and connected to a series of hyperbolic paraboloids through their common directrices, thereby leading the ensemble toward the four load-bearing points to the ground.
- In the following, the feet of perpendiculars dropped from points A, B, etc. on the parabola to the directrix will be denoted A ’, B ’, etc.
- The focus and directrix of a hyperbola were considered by Pappus.
Origin
Early 18th century: from medieval Latin, literally ‘directress’, based on Latin dirigere ‘to guide’.