# Quantum Mechanics Proof Homework Help

1. Jan 19, 2015

### SlushmanIU

I was asked to prove that any function u(z,t)=f(z-vt) is a solution of the wave equation

∂2u/ dt2= v2 · ∂2u/dz2

I know that v is constant and z and t are independent. I've tried looking at Lorentz law but I am getting nowhere fast. Please help!

2. Jan 19, 2015

### BvU

Hello Slushman, and welcome to the wonderful world of PF :)

We don't have many rules (just a bunch of well-meant guidelines, which please read). They do require (so you could construe that as a rule) some effort on your part in the sense that you show your attempt at solution. They also want you (so you could construe that as a rule as well -- but it's all well meant!) to use the template, which happened to disappear as if by magic from your post. Pity, I could have helped immediately, instead of tomorrow morning (it's late here, but perhaps others ...)

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

When I fill in the propposed solution, I get .....

3. Jan 21, 2015

### Goddar

Hi. This is pure mathematics so Lorentz has nothing to do with your proof:
How do you take the partial time-derivative of f(z-vt)? That is: f[z(t) -vt]?
Look up a calculus book if that's unfamiliar..

4. Jan 21, 2015

### BvU

Slushman still there ?