Question

已知全集U=R,集合A=｛x丨x∧2＞4｝,B={x丨x∧2 x－6≤0},则Cu（A∪B）=?

Answer 1

∵b={x|x2+x-6≤0},则x≤6-x2,
又∵a={x|x2＞4},∴6-x2＜2,b={x|x＜2}
∴a∪b={x|x＞4 or x＜2}
∴Cu(a∪b)={x|2≤x≤4}