# Need Help (not Homework question)

• Cluelessluke
In summary, Sakurai provides a derivation of the HUP and SE from using the [x,p] commutator, while ballentine provides a derivation of the HUP from using the [x,p] commutator and the product of the uncertainties of the two conjugate operators.
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!

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

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!

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.

the derivations can be found in almost any QM textbook

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.

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.

## 1. How do I know if I need help?

If you are struggling with a concept or task and are unable to find a solution on your own, it may be a sign that you need help. Additionally, if you feel overwhelmed or confused, seeking assistance can be beneficial.

## 2. Who can I ask for help?

You can ask a variety of people for help, depending on the specific issue. This could include your teacher or professor, a classmate, a tutor, a mentor, or a subject expert. It's important to reach out to someone who is knowledgeable and can effectively assist you.

## 3. What should I do before asking for help?

Before seeking help, it's important to make sure you have put in effort to solve the problem on your own. This could include reviewing class notes, doing additional research, or attempting the task multiple times. It's also helpful to identify specific areas where you are struggling so that you can effectively communicate your needs to the person you are seeking help from.

## 4. How do I ask for help?

When asking for help, it's important to be respectful and specific. Explain the issue you are having and what you have already tried. Be open to suggestions and actively listen to the person's advice. Remember to express gratitude for their assistance.

## 5. Is asking for help a sign of weakness?

No, asking for help is not a sign of weakness. In fact, it takes courage and self-awareness to recognize when you need assistance and seek it out. Asking for help can also lead to personal and academic growth, as well as foster positive relationships with others.

### Similar threads

• Quantum Physics
Replies
3
Views
959
• Quantum Physics
Replies
56
Views
3K
• Quantum Physics
Replies
17
Views
2K
• Quantum Physics
Replies
29
Views
2K
• Quantum Physics
Replies
17
Views
1K
• Quantum Physics
Replies
14
Views
1K
• Quantum Physics
Replies
6
Views
2K
• Quantum Physics
Replies
10
Views
1K
• Quantum Physics
Replies
3
Views
970
• Advanced Physics Homework Help
Replies
10
Views
945