Chapter 1.4, Problem 19E

U.S. FINANCIAL TRANSACTIONS The percentage of U.S. transactions by check between the beginning of $2001\left(t=0\right)$ and the beginning of $2010\left(t=9\right)$ is approximated by

$f\left(t\right)=-\frac{11}{9}t+43\left(0\le t\le 9\right)$

whereas the percentage of transactions done electronically during the same period is approximated by

$g\left(t\right)=\frac{11}{3}t+23\left(0\le t\le 9\right)$

a. Sketch the graphs of $f$ and $g$ on the same set of axes.

b. When did transactions done electronically first exceed those done by check?