Depreciation the rate of depreciation of a building is

Question

Depreciation the rate of depreciation of a building is given by D'(t) = 3000120 - t² dollars per year, 0 ≤ t ≤ 20; see the figure.

(a) Use the graph to find the total depreciation of the building over the first 10 years (t = 0 to t = 10).

(b) Use the definite integral to find the total depreciation over the first 10 years.