Question

已知拋物線y=x²-2x-3，若點(diǎn)P（-2，5）與點(diǎn)Q關(guān)于該拋物線的對(duì)稱軸對(duì)稱，則點(diǎn)Q的坐標(biāo)是    ．

Answer 1

【答案】分析：根據(jù)拋物線解析式求出拋物線對(duì)稱軸為x=1，再根據(jù)圖象得出點(diǎn)p（-2，5）關(guān)于對(duì)稱軸對(duì)稱點(diǎn)Q的縱坐標(biāo)不變，兩點(diǎn)橫坐標(biāo)到對(duì)稱軸的距離相等，都為3，得到Q點(diǎn)坐標(biāo)為（4，5）．
解答：解：∵x=-=-=1．
∴P（-2，5）關(guān)于對(duì)稱軸的對(duì)稱點(diǎn)Q的坐標(biāo)是（4，5）．
故點(diǎn)Q的坐標(biāo)是（4，5）．
點(diǎn)評(píng)：此題考查拋物線解析式與圖象性質(zhì)，以及軸對(duì)稱點(diǎn)的相關(guān)性質(zhì)，體現(xiàn)數(shù)形結(jié)合思想．