已知抛物线y=-x2+2x+2 (1)该抛物线的对称轴是_,顶点坐标是_; (2)若抛物线上两点A(x1,y1),B(x2,y2)的横坐标满足x1>x2>1,试比较y1与y2的大小.

问题描述:

已知抛物线y=-x2+2x+2
(1)该抛物线的对称轴是______,顶点坐标是______;
(2)若抛物线上两点A(x1,y1),B(x2,y2)的横坐标满足x1>x2>1,试比较y1与y2的大小.

(1)∵y=-x2+2x+2=-(x2-2x+1-1)+2=-(x-1)2+3,∴抛物线y=-x2+2x+2的对称轴为:x=1,顶点坐标为(1,3);(2)∵抛物线y=-x2+2x+2 的对称轴为x=1,图象开口向下,∴当x>1时,抛物线y=-x2+2x+2的y值随着x...