Question

Using straight-line depreciation, the value V of a particular computer x years after purchase is given by the linear function V(x) = 1,800 - 360x for 0 ≤ x ≤ 5.

(a) What are the independent and dependent variables?
(b) What is the domain of this linear function?
(c) What is the initial value of the computer?
(d) What is the value of the computer 2 years after purchase?
(e) Graph the linear function over its domain.
(f) After how long will the value of the computer be $0?

Answer 1

a) value is dependent and time is independent
b) domain is x between 0 and 5 inclusive
c) the value at x = 0 or 1800
d) 1800 - 360 (2) = 1080 is the value after 2 years
e) graph the points (0, 1800); (2, 1080) and draw a line between them
f) 360x = 1800
× = 5
it will be 0 after 5 years