From New Latin logarithmus, term coined by Scot mathematician John Napier from Ancient Greek λόγος (lógos, “word, reason”) and ἀριθμός (arithmós, “number”); compare rational number, from analogous Latin.
logarithm (plural logarithms)
- (mathematics) For a number , the power to which a given base number must be raised in order to obtain . Written . For example, because and because .
- For a currency which uses denominations of 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000, etc., each jump in the base-10 logarithm from one denomination to the next higher is either 0.3010 or 0.3979.
for a number x, the power to which a given base number must be raised in order to obtain x