The function is , where represents the number of years after .

(a)

The model is only valid from the year to .

Domain is

Range is

(b)

The number of households with only wireless phone service in .

The year is two after .

Observe the graph .

Find algebraically:

Substitute in .

.

The number of households with only wireless phone service in is millions.

(c)

Observe the graph:

-intercept is approximately .

Find algebraically:

Substitute in .

.

The -intercept is represents the number of millions of households with only wireless service in .

(d)

There is no zeros because there were more than zero households with only wireless phone service for all of the years in the domain.

(a). Domain is

Range is .

(b). The number of households with only wireless phone service in is millions.

(c). -intercept is . \ \ The -intercept is represents the number of millions of households with only wireless service in .

(d). There is no zeros because there were more than zero households with only wireless phone service for all of the years in the domain.