let be the identity(adsbygoogle = window.adsbygoogle || []).push({});

[tex] (2 \pi ) i^{m-1}D^{m} \delta (u) = \int_{-\infty}^{\infty} dx e^{iux}x^{m-1} [/tex]`

then making the replacement u=e^D D derivative with respect to 'x' then

[tex] (2 \pi ) i^{m-1}D^{m} \delta (e^{D})f(0) = \int_{-\infty}^{\infty} dx e^{ixe^{D}}x^{m-1}f(0)=\int_{-\infty}^{\infty} dx x^{m-1}\sum_{k=0}^{\infty}\frac{i^{k}f(n)}{n!} [/tex]

the problem is that i do not know how to define [tex] D^{m} \delta (e^{D}) [/tex]

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# Strange formula

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