standard_description: Construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values.
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