Cho hai tập hợp \(A = \left[ { – 4;3} \right),B = \left( { – 2; + \infty } \right).A\backslash B\) bằng:
A. \(\left[ { – 4; – 2} \right)\) B. \(\left\{ { – 4; – 3; – 2} \right\}\) C. \(\left[ {3; + \infty } \right)\) D. \(\left[ { – 4; – 2} \right]\)
\(A\backslash B = \{ x \in A|x \notin B\} \)
Ta có
\(A = \left[ { – 4;3} \right) = \left\{ {x \in \mathbb{R}\left| { – 4 \le x < 3} \right.} \right\};B = \left( { – 2; + \infty } \right) = \left\{ {x \in \mathbb{R}\left| {x > – 2} \right.} \right\}\)
Khi đó \(A\backslash B = \left\{ {x \in \mathbb{R}\left| { – 4 \le x < 3} \right.} \right\}\backslash \left\{ {x \in \mathbb{R}\left| {x > – 2} \right.} \right\} = \left\{ {x \in \mathbb{R}\left| { – 4 \le x < – 2} \right.} \right\} = [ – 4; – 2]\)
Chọn D