Sorry... my message got posted by mistake before I started typing. Here is what I was going to say:(adsbygoogle = window.adsbygoogle || []).push({});

I'm having a problem just understanding something from my quantum book. They're deriving something to do with a wave packet with the Schrodinger equation, and they have the equation of a wave packet at time t = 0:

[tex] \psi(x,0) = \int_{- \infty}^{+ \infty} dk A(k) e^{i(kx) [/tex]

where [tex] A(k) = e^{- \alpha (k - k_o)^2 / 2} [/tex]

They change variables to [tex]q' = k - k_o [/tex] and then they get

[tex] \psi(x,0) = e^{i k_o x} e^{- x^2 / {2 \alpha}} \int_{- \infty}^{+ \infty} dq' e^{- \alpha {q'}^2 / 2} [/tex]

I don't understand how they got that (specifically, the [tex] e^{-x^2 / {2 \alpha}} [/tex] term).

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Question about quantum

**Physics Forums | Science Articles, Homework Help, Discussion**