Logarithmic derivative

In mathematics, specifically in calculus and complex analysis, the logarithmic derivative of a function f is defined by the formula f ′ f {\displaystyle {\frac {f'}{f}}} where f ′ {\displaystyle f'} is the derivative of f.[1] Intuitively, this is the infinitesimal relative change in f; that is, the infinitesimal absolute change in f, namely f ′ , {\displaystyle f',} scaled by the current value of f.