Asymptote

Limit of the tangent line at a point that tends to infinity

In analytic geometry, an asymptote of a curve is a straight line such that the distance between the curve and the line approaches zero as one or both of the x or y coordinates tends to infinity. In projective geometry and related contexts, an asymptote of a curve is a line which is tangent to the curve at a point at infinity. The word "asymptote" derives from the Greek ἀσύμπτωτος (asumptōtos), which means "not falling together", from ἀ priv.

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