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?

linear
quadratic
logarithmic
exponential

A linear function is represented

Step-by-step explanation:

The table is:

x   f(x)

0   10.00

1    10.02

2   10.04

3   10.06

4   10.08

5   10.10

If we compute the difference between two consecutive function values and we divide it by the difference between their associated x values we get:

(10.02 - 10.00)/(1-0) = 0.02

(10.04 - 10.02)/(2-1) = 0.02

(10.06 - 10.04)/(3-2) = 0.02

(10.08 - 10.06)/(4-3) = 0.02

(10.10 - 10.08)/(5-4) = 0.02

This constant result indicates that a linear function is represented.

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50