The value of a certain piece of machinery depreciates over time according to the function , where is the estimated value in dollars after years, and corresponds to the time the machinery was purchased. The model is relevant for . If the graph of is plotted in the -plane, which of the following is the best interpretation of the -intercept of the graph in this context?
The machinery's value decreased by 20% each year.
The value of the machinery after 7 years is .
The initial purchase price of the machinery was .
The machinery depreciated to after some number of years.
