Given that the value of a copy machine decreases according to the function: v(t) = 11200(4)^(-0.12t), where, t is the number of years that have elapsed since the machine was purchased and v(t) is the cost of the machine in dollars. The time it takes for the machine to cost $2 800 can be determined by simply using the function and setting v(t) to be equal to $2 800. After calculating, the result is that the machine will cost $2 800 after 8.33 years of purchasing it.