As the coffee cools, temperature will drop...
But will it approach a constant temperature (a horizontal asymptote)?
Or will it drop without bound (such that as x → ∞, °F → − ∞)?
If you sketched a horizontal asymptote, then the limit should approach a constant value.
What does that horizontal asymptote represent? (use words)
If your sketch shows the temperature → −∞, then the limit does not exist, but approaches −∞.
What does that represent? (use words)