An office machine is purchased for $7200. Under certain assumptions, its salvage value, V, in dollars, is depreciated according to a method called double declining balance, by basically 73% each year, and is given by V(t) = 7200(073)^t, where t is the time, in years after purchase. a) Find V'(t). b) Interpret the meaning of V'(t). c) V'(t) = d) What is the meaning of V'(t)? V'(t) is the rate of change of savage value, t years after purchase. V'(t) is the number of years until the salvage value is zero. V'(t) is the salvage value t years after purchase. V'(t) is the rate at which the salvage value will increase over t years.