32.解:∵的图象与x轴交于点B(x1,0),C(x2,0),

∴                       .

又∵即,

∴                         .                        ①

又由y的图象过点A(2,4),顶点横坐标为,则有

                              4a+2b+c=4,                            ②

                              .                             ③

解由①②③组成的方程组得

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