How did math borrow 'factor' as in commercial agent?

91 Views Asked by At

I was researching factors as factor intermediaries, and its etymology on Etymonline.

factor (n.)

early 15c., "commercial agent, deputy, one who buys or sells for another,"
from Middle French facteur "agent, representative" (Old French factor, faitor "doer, author, creator"),
from Latin factor "doer, maker, performer," in Medieval Latin, "agent," agent noun from past participle stem of facere "to do" (from PIE root *dhe- "to set, put").
In commerce, especially "a commission merchant." Mathematical sense is from 1670s. Sense of "circumstance producing a result" is attested by 1816, from the mathematical sense.

  1. What "mathematical sense" "from 1670s" does Etymonline mean? 'Factor ' is too polysemous!
  1. Why did mathematicians in 1670s borrowed "factor"? Commission merchants in 1670s probably had to multiply and divide, but they also had to add and subtract too.
2

There are 2 best solutions below

0
On BEST ANSWER

It’s an extension of the sense ‘maker’ of Latin factor: a factor of a number is in a sense one of its ‘makers’, one of its constituent parts. This is the earliest mathematical sense noted in the OED Third Edition, which has this 1658 citation from George Atwell, The faithfull surveyour discovering divers errours in land measuring, and showing how to measure all manner of ground, and to plot it, and to prove the shutting by the chain onely ...:

Because there are four figures in the Fractions of the two Factours; therfore there are also four in the product.

0
On

Not a "why" answer, just some references. According to the "Earliest Known Uses of Some of the Words of Mathematics" pages:

FACTOR (noun). Fibonacci (1202) used factus ex multiplicatione (Smith vol. 2, page 105).

Factor appears in English in 1673 in Elements of Algebra by John Kersey: "The Quantities given to be multiplied one by the other are called Factors."

FACTOR (verb) appears in English in 1848 in Algebra by J. Ray: "The principal use of factoring, is to shorten the work, and simplify the results of algebraic operations." Factorize (spelled "factorise") is found in 1886 in Algebra by G. Chrystal [OED].

The Kersey reference correlates with the 1670s timeframe noted by Etymonline, and may at least hint at what was meant by "mathematical sense".