【導(dǎo)讀】解決直線與拋物線位置有關(guān)的簡單問題,進(jìn)一步體會數(shù)形結(jié)合的思想.相交于A,B兩點(diǎn),求證:.OAOB?過點(diǎn)一條直線L與拋物線??例2.已知直線與拋物線??交AB于點(diǎn)D,點(diǎn)D的坐標(biāo)為(2,1)求p的值。的直角頂點(diǎn)O為原點(diǎn),A、B在拋物線??上的點(diǎn)到直線AB的最段距離為__________. 上求一點(diǎn),使這點(diǎn)到直線45yx??