Recent content by lostinpitt

Thanks for all the help with this one. Thanks for the chain rule. The dirac chain rule you listed is actually listed in the textbook; it's only listed as a problem for the reader to prove; it's not explicitly listed as a Dirac Delta property to know, love, and apply. Anyway, using the...

Yes, that's what I meant for the first integral...I got frustrated and kept adding f(x) everywhere just to see if the preview would change. I must've forgot to erase one. Thanks for the heads-up about the previewer; at least now I know it's not something that I'm doing. I think that I'm...

Thanks for the help. I’m still working on the finer points of using LaTex…I hope this comes out correctly. Liboff suggests using the form (this should be integral{f(x)D(x)dx} = f(0) - I'm not sure why it's not showing this way). \int_{-\infty}^{+\infty}f(x)\delta(x)\mathrm{d}xf(x) = f(0)...

These problems are from Introductory Quantum Mechanics (Liboff, 4th Ed.) Note: I'm using "D" as the dirac delta function. 3.9 (a) Show that D( sqrt(x) ) = 0 This has me stumped. It is my understanding that the Dirac function is 0, everywhere, except at x=0. So, how can I show this to be...