# Homework Help: How can the uncertainty relation be written as such

1. Nov 1, 2015

### Abdul.119

1. The problem statement, all variables and given/known data
Show that the uncertainty relation can be written as
Δλ Δx >= λ^2 /4π

2. Relevant equations

3. The attempt at a solution
Ok the uncertainty relation is ΔpΔx >= h/2π , also p = h/λ , so substituting that I have Δh/λ Δx >= h/2π , then divide both sides by h, and multiply both sides by λ^2, so I get Δλ Δx >= λ^2 /2π , which is still not the same as the one given, I don't understand how the 2π becomes 4π

2. Nov 1, 2015

### Mister T

The minimum uncertainty is $\displaystyle \frac{\hbar}{2}$.

3. Nov 1, 2015

### Staff: Mentor

I don't understand what you are doing here. How can you have Δh?

4. Nov 1, 2015

### haruspex

I assume you mean Δ(h/λ) Δx, which is hΔ(1/λ) Δx
But that isn't what you did.
Δ(1/λ) is not the same as 1/Δλ. What does it turn into?

5. Nov 1, 2015

### Abdul.119

Right I had a mistake in the uncertainty relation that's why I was confused. I took care of it now, thank you for the help.