# Homework Help: Simple dirac notation problem

1. Nov 3, 2012

### Jalo

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

Imagine you have two vectors |a> and |b> such that:
|c> = |a> + |b>

Now imagine you want the dot product:

<c|a>

Is that the same as:

<c|a> = [ <a|*+<b|* ] |a> = <a*|a> + <b*|a>

where * represents the complex conjugate of the vector?

2. Relevant equations

3. The attempt at a solution~

Daniel

2. Nov 3, 2012

### Simon Bridge

You'd not normally put the star outside the bra like that.
if a is a state then |a> is the state vector corresponding to wavefunction Ya ... we may sometimes write |Ya> when you are starting out.

$<\psi_a|\psi>= \int \psi_a^\star \psi$

(I'm hoping someone else can do a better job of this explanation. :/ )
BTW: you know your vector |c> is not normalized right?

3. Nov 3, 2012

### Jalo

Yes, I'm aware that |c> is not normalized, but in this case it doesn't matter. I'm just learning the math behind Dirac's notation. I am not yet working with state vectors or anything of that kind.