1590s, "meeting at a point without intersecting," from Latin tangentem (nominative tangens), present participle of tangere "to touch," from PIE root *tag- "to touch, to handle; border on; taste, partake of; strike, hit;" figuratively "affect, impress; trick, cheat; mention, speak of" (cognates: Latin tactus "touch;" Greek tassein "to arrange," tetagon "having seized;" Old English taccian "stroke, strike gently"). First used by Danish mathematician Thomas Fincke in "Geomietria Rotundi" (1583). Extended sense of "slightly connected with a subject" is first recorded 1825. Related: Tangence; tangency.
tangent (n.)
1590s as a geometric function, from tangent (adj.). From 1650s as "a tangent line." Figurative use of off on a tangent is from 1771.
雙語例句
1. The conversation went off at a tangent.
交談突然偏離了正題。
來自柯林斯例句
2. The graph of a concave function is always below its tangent.
一個凹函數的圖象總在它的切線的下方.
來自辭典例句
3. The tangent may be used to find the direction.
這方向也可用正切求得.
來自辭典例句
4. For? 0 we naturally get a circle; for? 0 we obtain two tangent circles.
對? 0我們當然得到一個圓; 對? 0得到兩個相切的圓.
來自辭典例句
5. It's not easy to follow her thought because she's always going off at a tangent.