Final answer:
In the function representing the cost of sodas with free unlimited refills, the y-intercept is $3, indicating the initial cost, and the slope is 0 since the total cost does not increase with additional refills.
Step-by-step explanation:
The situation of charging $3 for a soda with free unlimited refills in a restaurant can be modeled as a function where the number of sodas is the independent variable (x) and the total cost is the dependent variable (y). In this model, whether you buy 1 or 100 sodas, the cost remains $3 because of the free refills. This constant cost is represented by the y-intercept in a linear function, which in this case is $3. Therefore, if we were to graph this relationship with the number of sodas on the x-axis and the total cost on the y-axis, the line would intersect the y-axis at $3. This means the y-intercept is $3, and the slope of this function would be 0, since the cost does not increase with the number of sodas consumed.