SearchOnMath

Another common definition of the exponential function to the natural basis, \(e^x\), comes from writing it as the series \(e^x = \sum_{k=0}^{\infty} \frac{x^k}{k!}\).

A famous irrational number, \(\pi = \frac{C}{d}\) is defined by the ratio of a circle's circumference (\(C\)) to its diameter (\(d\)).

Shannon's entropy, \(H(X) = -\sum_{x \in \mathbf{X}} p(x) \log p(x)\), measures how informative the mass function \(p\) is about the occurrence of the possible values of variable \(X\).