# Complex numbers/matrix

1. Feb 1, 2012

### v_pino

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

I'm part way through a problem and got the answer $$P_x=c_+^* c_-+c_-^*c_+$$.
But the answer should be $$2Re(c+^*c_-)$$.

Are the two equivalent?

2. Relevant equations

$$c+c^*=2Re(c)$$

2. Feb 2, 2012

### Redbelly98

Staff Emeritus
That depends. Is c-*·c+ equal to (c+*·c-)* ? If so, then you can apply:

3. Feb 2, 2012

### conquest

Just complex conjugate on of the both terms