When the US Federal government spends more money than it takes in, the amount of the difference is called the deficit. In Figure 1.13, the function D = f(t) gives a good approximation of the deficit from 2011 to 2015, where D is the deficit in billions of dollars and t is the number of years since 2010. 

(a) Is the deficit increasing or decreasing over this time period? 

(b) Interpret f(4) = 485 in terms of the deficit. 

(c) In Figure 1.13, label the axes and put a dot at the point identified in part (b). 

(d) If we extended the domain of this function to include a vertical intercept, what would the vertical intercept represent? 

(e) If we extended the domain of this function to include a horizontal intercept, what would the horizontal intercept represent?

Figure 1.13

Transcribed Image Text:

billion $ D = f(t) t (years since 2010)