I have not understood what the AC load line for a BJT is and while drawing the AC load line for a BJT, the collector emitter voltage ***VCE*** and the collector current ***IC*** are related as,

***IC = -VCE / (RC // RL)***

Where ***RC*** is collector resistance and ***RL*** is the load resistance.

So, according to this equation, the load line should pass through origin but that does not happen. Why doesn’t it happen?

Thank you.