Tích phân I = 4 ∫ 0 | x − 2 | dx bằng:

Đáp án đúng là: D

\[\begin{array}{l}I = \int\limits_0^4 {\left| {x - 2} \right|{\rm{d}}x} = \int\limits_0^2 {\left| {x - 2} \right|{\rm{d}}x} + \int\limits_2^4 {\left| {x - 2} \right|{\rm{d}}x} = - \int\limits_0^2 {\left( {x - 2} \right){\rm{d}}x} + \int\limits_2^4 {\left( {x - 2} \right){\rm{d}}x} \\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \left. {\left( { - \frac{{{x^2}}}{2} + 2x} \right)} \right|_0^2 + \left. {\left( {\frac{{{x^2}}}{2} - 2x} \right)} \right|_2^4 = 4.\end{array}\]