*Good evening and welcome to Tool Week on Word of the Day! A journey through the English vocabulary and the words that piqued my interest are the titles of Tool songs, in WotD we'll be learning a new word for each working day of the week, except holidays, unless there's a holiday special...*

**Today's word is:**

### Parabola

|pə-ra-bə-lə|

**Noun**

- a plane curve generated by a point moving so that its distance from a fixed point is equal to its distance from a fixed line
**:**the intersection of a right circular cone with a plane parallel to an element of the cone

- something bowl-shaped (as an antenna or microphone reflector)

Also, track five on Tool's third album, *Lateralus*

*"This body. This body holding me. Be my reminder here that I am not alone in**This body, this body holding me, feeling eternal**All this pain is an illusion."*

**ORIGIN:** 16th cent.: New Latin, from Greek *parabolē**,* literally, comparison; First Known Use: 1579

### Getting Technical

A **Parabola **is an open curve, one of the conic sections. It results when a right circular cone intersects a plane that is parallel to an edge of the cone. It is also the path of a point moving so that its distance from a fixed line (directrix) is always equal to its distance from a fixed point (focus). In analytic geometry its equation is ** y = ax^{2} + bx + c **(a second-degree, or quadratic, polynomial function). Such a curve has the useful property that any line parallel to its axis of symmetry reflects through its focus, and vice versa. Rotating a parabola about its axis produces a surface (paraboloid) with the same reflection property, making it an ideal shape for satellite dishes and reflectors in headlights. Parabolas occur naturally as the paths of projectiles. The shape is also seen in the design of bridges and arches.