standard_description: Recognize that sequences are functions, sometimes defined recursively, whose domain is a subset of the integers. For example, the Fibonacci sequence is defined recursively by f(0) = f(1) = 1, f(n+1) = f(n) + f(n-1) for n ³ 1.
problem_activity: Task
Suppose a can of cold soda is left in a warm room on a summer day.  The graph below shows the temperature of the soda as it gradually increased:
[IMG]
The function that describes the temperature, $F$, of the soda (in degrees Fahrenheit) after $t$ minutes can be expressed by
$$F(t)=C - R e^{-kt},$$
for some positive values of $C$, $R$, and $k$.<
Use the graph to estimate $C$.
Use the graph to estimate $R$.
What was the approximate room temperature?  What was the initial temperature of the soda when placed in the room?


aligns: no