Question

11．如圖所示的陰影部分可用二元一次不等式組表示為$\left\{\begin{array}{l}{x-y≥0}\\{x+y＞0}\end{array}\right.$或$\left\{\begin{array}{l}{x-y≤0}\\{x+y＞0}\end{array}\right.$．

Answer 1

分析 根據(jù)不等式組表示平面區(qū)域，即可確定陰影部分的對(duì)應(yīng)的不等式組．

解答 解：由圖象可知陰影部分在直線y=x的下方，直線y=-x的上方，或在直線y=x的上方，直線y=-x的下方
∴對(duì)應(yīng)的不等式組為$\left\{\begin{array}{l}{y≥x}\\{y＜-x}\end{array}\right.$或$\left\{\begin{array}{l}{y≥x}\\{y＜-x}\end{array}\right.$，即$\left\{\begin{array}{l}{x-y≥0}\\{x+y＞0}\end{array}\right.$或$\left\{\begin{array}{l}{x-y≤0}\\{x+y＞0}\end{array}\right.$，
故答案為：$\left\{\begin{array}{l}{x-y≥0}\\{x+y＞0}\end{array}\right.$或$\left\{\begin{array}{l}{x-y≤0}\\{x+y＞0}\end{array}\right.$．

點(diǎn)評(píng) 本題主要考查二元一次不等式組表示平面區(qū)域，比較基礎(chǔ)．