Integral homework problems


by Apteronotus
Tags: homework, integral
Apteronotus
Apteronotus is offline
#1
Nov17-10, 08:47 AM
P: 196
Hi everyone,

Can anyone show me how the property
[tex]\frac{1}{2\pi} \int ^{\infty} _{-\infty} e^{i\omega x}d\omega= \delta(x)[/tex]
holds.

Thanks,
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g_edgar
g_edgar is offline
#2
Nov17-10, 09:32 AM
P: 608
Do you know about Schwartz distribution theory? Generalized functions? Because that is what you are writing about, not traditional calculus functions. Your equation MEANS...

[tex]
\frac{1}{2\pi}\int_{-\infty}^\infty e^{i\omega x} \phi(x)\,d\omega = \phi(x)
[/tex]

for all test functions [itex]\phi[/itex] from an appropriate class.
Apteronotus
Apteronotus is offline
#3
Nov17-10, 11:15 AM
P: 196
edgar thanks for your reply.
It seems I've stumbled on something beyond my means.
I dont know anything about Schwartz distribution theory and a quick search on the net didnt help at all.

I thought the integral would be an easy calculus identity of sorts. Can you show me why the integral holds?


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