DiracDelta

DiracDelta[x] represents the Dirac delta function δ(x).

DiracDelta[x1,x2,…] represents the multidimensional Dirac delta function δ(x1,x2,…).

Examples

Integrate a function with DiracDelta:

Integrate[f[x] DiracDelta[x - a], {x, -Infinity, Infinity}]
(* f[a] *)

Please visit the official Wolfram Language Reference for more details.