logarithm The logarithm of a number or variable x to base b, logb x, is the exponent of b needed to give x. The bases most commonly used in mathematics are e and 10. A logarithm to base e, written as log x or ln x, is known as a natural logarithm. A logarithm to base 10 is written as log10 x and is known as a common logarithm. Related category MATHEMATICS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |