Question

Juan recently entered into a contract for a cell phone plan. The table shows the monthly cost in dollars, f(x), if Juan sends x text messages.



What type of function is represented?
x - 0 , 1 , 2 , 3 , 4 , 5
f(x) 10.00 , 10.02 , 10.04 , 10.06 10.08 10.10 linear
quadratic
logarithmic
exponential

Answer 1

Linear. The cost increases by a constant $0.02$ per text (first differences are all $0.02$), so f(x)=10+0.02x.