【導(dǎo)讀】;③若點(diǎn)D在第二、四象限坐標(biāo)軸夾角平分線上,若點(diǎn)與點(diǎn)關(guān)于x軸對(duì)稱,則a=,請(qǐng)?jiān)谌鐖D所示的網(wǎng)格平面內(nèi)作平面直角坐標(biāo)系;請(qǐng)作出△ABC關(guān)于y軸對(duì)稱的△A′B′C′;9.(12分)如圖,在平面直角坐標(biāo)系xOy中,已知點(diǎn)A(-1,求出△ABC的面積;點(diǎn)A1,B1,C1的坐標(biāo)分別為(1,5),(1,0),13.(16分)如圖所示,在長(zhǎng)方形ABCD中,作點(diǎn)P1關(guān)于點(diǎn)B的對(duì)稱點(diǎn)P2,作點(diǎn)P2關(guān)于點(diǎn)C的對(duì)稱點(diǎn)P3,作點(diǎn)P5關(guān)于點(diǎn)B的對(duì)稱點(diǎn)P6……按此操作下去,則點(diǎn)P2015