tangent

(tănˈjənt)

1. Making contact at a single point or along a line; touching but not intersecting.
2. Irrelevant.

1. A line, curve, or surface meeting another line, curve, or surface at a common point and sharing a common tangent line or tangent plane at that point.
2. Abbr. tan Mathematics The trigonometric function of an acute angle in a right triangle that is the ratio of the length of the side opposite the angle to the length of the side adjacent to the angle.
3. A sudden digression or change of course: went off on a tangent during the courtroom argument.
4. Music An upright pin in a keyboard instrument, especially in a clavichord, that rises to sound a string when a key is depressed and stops the string at a preset length to set the pitch.

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tangent

tan Θ= ^a/_b