220px|right|thumb|Tangent to a curve. The red line is tangential to the curve at the point marked by a red dot. 220px|right|thumb|Tangent plane to a sphere
A tangent is a line or plane that touches a curve or surface at exactly one point without crossing through it. Tangents matter because they help mathematicians and scientists describe how curves and surfaces change direction at specific points, which is essential for understanding motion, slopes, and the behavior of shapes.
AI-generated from the Wikipedia summary — may contain errors.
220px|right|thumb|Tangent to a curve. The red line is tangential to the curve at the point marked by a red dot. 220px|right|thumb|Tangent plane to a sphere
In geometry, the tangent line (or simply tangent) to a plane curve at a given point is, intuitively, the straight line that "just touches" the curve at that point. Leibniz defined it as the line through a pair of infinitely close points on the curve. More precisely, a straight line is tangent to the curve at a point if the line passes through the point on the curve and has slope , where f is the derivative of f. A similar definition applies to space curves and curves in n-dimensional Euclidean space.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).