nousername

Hey,

I have this math investigation task which asks us to model the cooling of coffee in three different cups over a period of time. Anyway, i got the data, did a scatter plot and found the exponential model, but i dont know how i could determine which one has the greatest rate of cooling.

I know that I need to look at the slope, but they dont all start from the same point on the graph, so i cant determing which one has the fastest rate of decay. If they all started from the same point i would be able to see the different functions branching off from that point, and if one has a steeper slope than the other i would know, but this wasnt the case. Can someone please help! Thanks.