Math. [ad. mod.L. subtangens, -entem: see SUB- 1 and TANGENT.] That part of the axis of a curve which is contained between the tangent and the ordinate.
1715. Phil. Trans., XXIX. 196. He determines the Proportion of the Subtangent to the Ordinate.
1798. Hutton, Course Math., II. 306. The Method of Tangents, is a method of determining the quantity of the tangent and subtangent of any algebraic curve; the equation of the curve being given.
1816. trans. Lacroix’s Diff. & Int. Calculus, 75. The line PS will constantly tend to become equal to the subtangent PT.
1827–8. Hamilton, in Encycl. Metrop. (1845), I. 740/1. The subtangent is bisected by the curve, whether the coordinates are rectangular or oblique.
