unit6 (1) How do we Chinese people celebrate our National Day? (2) What do you mean by two New Years in China? (3) Why is the Spring Festival more enjoyable than the New Year's Day?
【简答题】抛物线C的方程为 ,过抛物线C上一点 P ( x 0 , y 0 )( x 0 ≠0)作斜率为k 1 ,k 2 的两条直线分别交抛物线C于A( x 1 , y 1 )B( x 2 , y 2 )两点( P ,A,B三点互不相同),且满足 . (Ⅰ)求抛物线C的焦点坐标和准线方程; (Ⅱ)设直线AB上一点M,满足 ,证明线段 P M的中点在 y 轴上; (Ⅲ)当 =1时,若点 P 的坐标为(1,-1...