Question

已知A={x|x^2+a1x+b1=0},B={x|x^2+a2x+b2=0},全集为R,试用A,B的交,并,补集表示下

Answer 1

(1)U1={x|x^2+a1x+b1=0 or x^2+a2x+b2=0}=A并B

(2)U2={x|(x^2+a1x+b1）^2=0 and (x^2+a2x+b2)^2=0}={x|(x^2+a1x+b1）=0 and (x^2+a2x+b2)=0}=A交B

(3)U3=A的补

(4)U4={x|(x^2+a1x+b1）^2≠0 or (x^2+a2x+b2)^2≠0}={x|(x^2+a1x+b1）^2≠0}并={x|(x^2+a2x+b2)^2≠0}=A的补 并 B的补