The value of an automobile purchased in 2014 can be approximated by the function V (t) = 30(0.85)^t, where t is the time, in years, from the date of purchase, and V (t) is the value, in thousands of dollars.
(a) Evaluate and interpret V (4), including units.
(b) Find an expression for V ¨(t), including units.
(c) Evaluate and interpret V ¨(4), including units.
(d) Use V (t), V ¨(t), and any other considerations you think are relevant to write a paragraph in support of or in opposition to the following statement: “From a monetary point of view, it is best to keep this vehicle as long as possible.”