Finding AC voltage across Resistor

[Acuben]

Homework Statement

I have three questions
1. How do you find AC voltage across resistor when there are both AC and DC current?
2. is AC voltage across a resistor different from voltage across a resistor?
3. Find AC voltage across Resistor (in this image)
http://img199.imageshack.us/i/acv.gif/
load line Eq: V(ec)=12-6000*I(c)
answer: 1.08v

Homework Equations

Voltage across resistor = I*R
but I do not know if this can be used when there are mixture of

The Attempt at a Solution

well I tried making a AC current by removing battery out of the circuit. I would still get around 3 volts. Also tried using V(max) and V(min) and calculated for I*R(l), but got around 6 volts (which is way off)
now I'm out of ideas. (well I do not understand the problem fully in the first place)
Do I need to use the chart on the bottom?
by the way, does this topic (or anything under circuits, electric fields, and optics-related physics) belong to advanced physics? or is this in the right section?)

 

[Acuben]

can I simply find
I(c) max and I(c) min and find both voltage of V(ec) then find the difference divided by 2?