# Convolution of two dirac delta functions

Why mathematica doesnt produce any answer to the following integral?

Integrate[0.040608386793220284*DiracDelta[w]*DiracDelta[-w + x], {w, -2, 2}]


and how can I get a solution?

Thank you very much.

Integrate[0.0406*DiracDelta[w]*DiracDelta[-w + x], {w, -Infinity, Infinity}]

0.0406 DiracDelta[x]

• then specify x.. it can't know the value unless it knows x. Observe that Integrate[0.0406*DiracDelta[w]*DiracDelta[-w + 100], {w, -2, 2}] gives 0. – bill s Oct 18 '13 at 15:18