Coolant Leak

I have a 95 Tahoe, there are two hoses running to the core at the firewall in the engine compartment and one other hose next to those two. It has a rubber elbow sticking out and that is where the coolant is coming from not connected to anything. I happens right after I've driven the truck and park it in the yard. If the leak is not from the core and coming from this other line, what is this third hose the coolant is coming from and how do I know for sure it's my heater core.