the.com/tangent
the line that kisses a curve once, then commits fully to leaving
means A straight line that touches a curve at a single point without crossing it; figuratively, a sudden swerve off the main subject onto a loosely related one.
from From Latin tangentem, the present participle of tangere, 'to touch' — the same root that gives us tangible, tactile, and contact. Geometers borrowed it (via the phrase linea tangens, 'the touching line') for the line that grazes a curve at exactly one point. The conversational sense, 'going off on a tangent,' came later by metaphor: just as the line touches and departs, a speaker brushes the topic and shoots off in another direction.
- single touch
- meets a curve at exactly one point locally
- word origin
- from Latin tangere, to touch
- trig star
- tangent equals sine divided by cosine
- infinite spike
- shoots to infinity at ninety degrees
- conversation hazard
- derailing chats stole this geometric term
apollo 13 oxygen tank — explosion in 1970 forced mission abort, became symbol of going off course
tesla stock price movements — elon musk's tweets send shares on tangents, e.g. 2021 $420 'funding secured' post