deltasquared
Deltasquared, often denoted Δ^2 or spoken as "delta squared," is a concept in discrete mathematics and numerical analysis referring to the second finite difference operator applied to a real-valued function defined on a discrete domain. It captures the change in the rate of change of the function, effectively measuring discrete curvature.
Definition: For a function f defined on the integers, the first difference is Δf(n) = f(n+1) − f(n).
Properties and uses: Δ^2 is linear, since Δ is linear. It is a discrete analogue of the continuous
See also: finite difference method; discrete second derivative; binomial expansion of Δ; note that Δ^2 is not