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

The numbers represent the years.

**(a)** Find , , and .

Substitute in .

.

Substitute in .

.

Substitute in .

.

represents the revenue for the year is million dollars.

represents the revenue for the year is million dollars.

represents the revenue for the year is million dollars.

**(b)** Find .

.

**(c)** Find , , and .

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

The numbers represent the years.

Substitute in .

.

Substitute in .

.

Substitute in .

.

represents the revenue for the year is million dollars.

represents the revenue for the year is million dollars.

represents the revenue for the year is million dollars.

**(d)**

means 5 years prior to year .

In the model , represents five years after .

**(e)**

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

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

An advantage in using the model instead of the model :

The model is used to determine the total projected world wide digital music revenue for the years after , where as when the model is used we can determine the revenue from the year .

**(a)**

represents the revenue for the year is million dollars.

represents the revenue for the year is million dollars.

represents the revenue for the year is million dollars.

**(b)**

.

**(c)**

represents the revenue for the year is million dollars.

represents the revenue for the year is million dollars.

represents the revenue for the year is million dollars.

**(d)**

In the model , represents five years after .

**(e)**

The model is used to determine the total projected world wide digital music revenue for the years after , where as when the model is used we can determine the revenue from the year .

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