# Homework Help: Amplitude for a particle in state

1. Sep 30, 2006

### Agnostic

<-z|x> is the amplitude for a particle in state |x> to be in state |-z>.

a particle in state |x> can be in |+x> or |-x>, correct?

|+x> = [1/sqrt(2)]|+z> + [1/sqrt(2)]|-z>

|-x> = [1/sqrt(2)]|+z> - [1/sqrt(2)]|-z>

How would this be calculated?

Would the amplitude be:

<-z|+x> + <-z|-x>?

|<-z|+x>| + |<-z|-x>|?

2. Oct 2, 2006

### dextercioby

I've never seen the $|-z\rangle$ notation before. But $-|z\rangle$ is a common one.

Daniel.

3. Oct 4, 2006

### jonesy101

I've used this notation before, but there was always a differentiation between |+x> and |-x>, I never saw just |x>. Perhaps |x> means |+x>?

If this is the case in order to get the amplitude you want <-z|+x>. Only do |<-z|+x>| for the probablility.