
已知數(shù)軸上兩點(diǎn)A,、B對(duì)應(yīng)的數(shù)分別為-1,、3,,點(diǎn)P為數(shù)軸上一動(dòng)點(diǎn),其對(duì)應(yīng)的數(shù)為x.
(1)若點(diǎn)P到點(diǎn)A,、點(diǎn)B的距離相等,,求點(diǎn)P對(duì)應(yīng)的數(shù);
(2)數(shù)軸上是否存在點(diǎn)P,,使點(diǎn)P到點(diǎn)A,、點(diǎn)B的距離之和為8?若存在,,請(qǐng)求出x的值,;若不存在,說明理由,;
(3)現(xiàn)在點(diǎn)A,、點(diǎn)B分別以2個(gè)單位長(zhǎng)度/秒和0.5個(gè)單位長(zhǎng)度/秒的速度同時(shí)向右運(yùn)動(dòng),點(diǎn)P以6個(gè)單位長(zhǎng)度/秒的速度同時(shí)從O點(diǎn)向左運(yùn)動(dòng).當(dāng)點(diǎn)A與點(diǎn)B之間的距離為3個(gè)單位長(zhǎng)度時(shí),,求點(diǎn)P所對(duì)應(yīng)的數(shù)是多少,?