The identric mean of two positive real numbers x, y is defined as:[1] It can be derived from the mean value theorem by considering the secant of the graph of the function
x ↦ x ⋅ ln x
{\displaystyle x\mapsto x\cdot \ln x}
It can be generalized to more variables according by the mean value theorem for divided differences.
The identric mean is a special case of the Stolarsky mean.