Mathematics in Ancient and Medieval India c5.s4.1

c5.s4.1

The expression log ₂ 8 = 3 means the number 8 can be divided by 2 three times. This was defined by Napier (1550–1617) who has been given priority with regard to the publication of a table of logarithms and an account of their meaning and use. In the earliest centuries of the Christian era Jainas (vide *Dhavalā* commentary of Vīrasenācārya) conceived the idea of logarithms to the base 2, 3, 4, though no general use of the idea seems to have been made by them. They used *ardhaccheda*, *tṛkaccheda*, *caturthaccheda* of a number, as the number of times it can be divided by 2, 3, 4, etc. For instance *ardhaccheda* of x = log ₂ x, *tṛkaccheda* of x = log ₃ x etc. Moreover, there is evidence in the *Dhavalā*² commentary that the following rules were known to them.