noun
- The logarithm of the reciprocal of a number; the negative of the logarithm of that number.
Usage: mathematics; technical; largely historical; replaced by modern notation in contemporary mathematics
Examples
- The cologarithm of 10 is the negative of the logarithm of 10.
- In older mathematical texts, cologarithms were used to simplify division calculations.
- The cologarithm of a number x equals log(1/x).
- Before electronic calculators, mathematicians relied on cologarithm tables for complex computations.