# Complex analysis in electrical circuits

1. Dec 13, 2011

### nhmllr

When discussing the i (the imaginary unit) in a math class, my math teacher commented that that complex analysis is used in studying electrical circuits. I know a little about resistors and what not, but never have I seen complex analysis used this way. I've tried looking it up, but it's been fruitless. Has anybody else heard of this? What was he talking about?

Thanks.

2. Dec 13, 2011

### clem

Alternating current

3. Dec 13, 2011

### nhmllr

Ah. Thanks.

4. Dec 14, 2011

### Termotanque

In general, complex impedance.

5. Dec 14, 2011

### technician

This is a useful application in physics dealing with oscillations.
In analyzing complex numbers it is possible to show a relationship
e^iwt = Cos(wt) + iSin(wt)
This means that a physics expression such as V = VoCos(wt) can be written as the real part of a complex number Vo x e^iwt
Doing this means that you are dealing with exponential functions rather than Cosine and sine functions ....it is easier