用適當(dāng)?shù)姆?hào)填空:
用適當(dāng)?shù)姆?hào)填空:
用適當(dāng)?shù)姆?hào)填空:
(1)√a²___{-a,a}
(2) {(x,y)|y=|x|}___{(x,y)|y=x,x>0}
(3){x||x-1|
優(yōu)質(zhì)解答
(1)√a²_∈__{-a,a}
(2) {(x,y)|y=|x|}_包含__{(x,y)|y=x,x>0}
(3){x||x-1|(3){x| |x-1|<1}___0;沒有這種符號(hào)那兩分開來的。|x-1|<1∴ -1