# Homework Help: Opposite of a complex question

1. Jan 25, 2010

### nhrock3

$$(\frac{1}{0.81e^{j0.27}})*$$=$$\frac{1}{0.81}e^{j0.27}$$
why we can remove the constant?
why the conjugate of a complex number is multiplication of the angle by -1

2. Jan 25, 2010

### elibj123

Complex conjugation is distributive over multiplication, and a real number is not affected by it, therefore you can pull the constant out.

The angle thing comes from euler's formula:

$$e^{j\theta}=cos(\theta)+jsin(\theta)$$

So

$$(e^{j\theta})*=cos(\theta)-jsin(\theta)=cos(-\theta)+jsin(-\theta)=e^{-j\theta}$$