1. The plural of cologarithm; a mathematical function equal to the negative of a logarithm, or equivalently, the logarithm of the reciprocal of a number.
Usage: mathematics; archaic or specialized; largely superseded by modern notation and calculators

Examples

• In older mathematical texts, cologarithms were used to simplify multiplication and division calculations.
• The cologarithm of a number x is equal to log(1/x).
• Before electronic calculators, engineers relied on cologarithm tables to speed up complex computations.
• The concept of cologarithms is rarely taught in modern mathematics curricula.