Properties of Differential Operator

From ProofWiki
Jump to navigation Jump to search



Theorem

The differential operator $D$ has the following properties:

\(\text {(1)}: \quad\) \(\ds \dfrac {\map f x} D\) \(=\) \(\ds \int \map f x \rd x\)
\(\text {(2)}: \quad\) \(\ds \dfrac {x^n} {\paren {D + p}^q}\) \(=\) \(\ds \paren {1 + \dfrac D p}^{-q} \dfrac {x^n} {p^q}\)
\(\text {(3)}: \quad\) \(\ds \map F D e^{a x}\) \(=\) \(\ds e^{a x} \map F a\)
\(\text {(4)}: \quad\) \(\ds \map F D e^{a x} \map f x\) \(=\) \(\ds e^{a x} \map F {D + a} \map f x\)
\(\text {(5)}: \quad\) \(\ds \map F {D^2} \sin a x\) \(=\) \(\ds \map F {-a^2} \sin a x\)
\(\text {(6)}: \quad\) \(\ds \map F {D^2} \cos a x\) \(=\) \(\ds \map F {-a^2} \cos a x\)


Proof




Sources