题目

Life affects (影响) friendships. As we grow, marry, fight in wars, move across the country or change jobs, old friendships fall away and new ones form. As long as we live, the things around us change, and as long as things change, friendships are affected. When we were children we had best friends. No matter what happened we were still friends. We live our lives, however, and do what life calls for us to do, and as we get older, memories fade (逐渐消失), faces blur (变得模糊不清), and even friends' names from childhood are forgotten. Do you have a question about friendship?已知抛物线y=ax2+bx+c与y轴的交点为C，顶点为M，直线CM的解析式y=-x+2并且线段CM的长为22，（1）求抛物线的解析式．（2）设抛物线与x轴有两个交点A（x1，0）、B（x2，0），且点A在B的左侧，求线段AB的长．