a. 2.3
12. The piecewise function below gives the cost f(x) of x text messages per
month. Which would be the least expensive plan for a person who
had d text messages: a plan in which c = 31 or a plan in which c = 40?
Explain.
C
- {₁+
f(x) =
when x ≤ d
c + p(x - d) when x > d
10-2 Elect