What does the horizontal line (asymptote) represent?
The line appears to be the lowest temperature that the water can reach.
In a room, the lowest temperature that something can reach is the temperature of the room.
How would the graph be different if the cup of hot water was left outside during winter instead?
If a cup were outside in the cold, the lowest temperature that the liquid could reach would still be the temperature of its surroundings.
The asymptote would be lower, but still parallel to the
If the temperature outside was below zero, the asymptote would be below the