# Homework Help: Normalising a Wave Function

1. Feb 27, 2010

### Lavace

1. The problem statement, all variables and given/known data
http://www.ph.qmul.ac.uk/~phy319/problems/problems1.doc"
Question 2)b

3. The attempt at a solution

http://img685.imageshack.us/img685/9033/p270210111001.jpg [Broken]

Is this correct?

Thanks!

Last edited by a moderator: May 4, 2017
2. Feb 27, 2010

### vela

Staff Emeritus
No. The parameter $\alpha$ should appear in the answer. Your set-up looks fine, though.

3. Feb 27, 2010

### Lavace

But once we take out the infinity terms after the integral, we're left with the $\alpha$ terms, one is + and one is -, so they cancel.

What is it I'm doing wrong here?

Thanks!

4. Feb 27, 2010

### vela

Staff Emeritus
They can't cancel or else you'd be left with N2x0=1, which has no solution. Recheck the sign on each term.

5. Feb 27, 2010

### Lavace

I can't seem to find the problem, anyone care to take a look?

The only reason I can think of is the original way I set up the integrals, and whether I add them or subtract them!

6. Feb 27, 2010

### vela

Staff Emeritus
$$\left[\frac{1}{-2\alpha}e^{-2\alpha x}\right]^\infty_0 \ne -\frac{1}{2\alpha}$$

7. Feb 27, 2010

### Lavace

Ahhhhhh, I see now, thank you VERY much! :) Let the studying continue!