subˈduplicate, a. Math.
[sub- 10.]
1. Of a ratio or proportion: Being that of the square roots of the quantities; thus, 2 : 3 is the subduplicate ratio of 4 : 9.
| 1656 tr. Hobbes' Elem. Philos. 121 A Proportion is said to be Divided, when between two quantities are interposed one or more Means in continual Proportion, and then the Proportion of the first to the second is said to be Subduplicate of that of the first to the third, and Subtriplicate of that of the first to the fourth. 1670 Boyle Usef. Exp. Nat. Philos. ii. iii. 15 The times are in Subduplicate Proportion to the lengths of the Pendulums. 1674 Petty Disc. Dupl. Prop. 21 The First Instance, Wherein Duplicate, and Sub-duplicate Ratio or Proportion is considerable, Is In the Velocities of two equal and like Ships; which Velocities..are the square Roots of the Powers which either drive or draw them. 1706 W. Jones Syn. Palmar. Matheseos 288 The Times in which a Body runs thro' those Planes, shall be in a Subduplicate Ratio of their Altitudes. 1798 Hutton Course Math. II. 358 The bodies descend by nearly uniform velocities, which are directly in the subduplicate ratio of the diameters. |
¶ 2. = subduple. (A misuse.)
| 1656 Hobbes Six Lessons Wks. 1845 VII. 277 It is the same fault when men call half a quantity subduplicate. 1755 Johnson, Subduplicate,..containing one part of two. |