# Need Help (not Homework question)

1. Feb 6, 2009

### Cluelessluke

Hey everyone. I would love for someone to show me quite clearly how to derive $$\Delta$$x$$\Delta$$p$$\geq$$$$\frac{\hbar}{2}$$ and separately how to derive the Schrodinger Equation both from using the [x,p] commutator. With $$\hat{x}$$=i$$\hbar$$$$\frac{\partial}{\partial p}$$ and $$\hat{p}$$=p (in momentum space). Thanks in advance for anyone's help!

2. Feb 6, 2009

### malawi_glenn

i am actually planning to write both those derivation in LaTeX tomorrow, since those are very frequently asked questions.

3. Feb 6, 2009

### Cluelessluke

Awesome! Thanks so much. If it wouldn't be too much to ask, maybe you could post a link to it in this thread? Thanks again!

4. Feb 6, 2009

### Brian_C

The derivation can be found in Sakurai. There is an equation relating the product of the uncertainties of two conjugate operators to the commutator of the operators. Substituting the [x,p] commutator yields the HUP.

5. Feb 6, 2009

### malawi_glenn

the derivations can be found in almost any QM textbook

6. Feb 10, 2009

### Cluelessluke

So I looked throughout my quantum textbook but there is not a derivation of these two processes specifically in there. malawi_glenn, I was wondering if you were able to LaTeX those fellas yet or not. Thanks for your time.

7. Feb 10, 2009

### malawi_glenn

which book do you have? I have sakurai - modern QM, and it derives both HUP and SE. In my opinion, it is THE quantum mechanics textbook. But since it is dealing with a second course in QM, it requires "the basics" so in that opinion "Quantum Mechanics - a modern development " by ballentine is better, but if you can a copy of sakurais book - you have everything you need.

Well we got some library items done on the HUP atleast, shrödinger will be next weekend.

There are a lot of old threads regarding the derivation of SE, you can search for those meanwhile.

This is the item I did, https://www.physicsforums.com/library.php?do=view_item&itemid=207 you perhaps need to study the three first items under "see also" (to the right) which I also did.

Enjoy, and please tell me/us is a step which you can't understand.