2025年中考数学二轮专题复习- 专题六 二次函数综合高效拆分特训（含解析）

中小学教育资源及组卷应用平台 2025年中考二轮专题复习-二次函数压轴题高效拆分特训 专题六 二次函数综合高效拆分特训 INCLUDEPICTURE"标1.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标1.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标1.tif" \* MERGEFORMATINET 特训30　二次函数中的定点问题INCLUDEPICTURE"标2.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE"条单.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\条单.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\条单.tif" \* MERGEFORMATINET 方法整合 利用几何性质、根与系数的关系，将动直线y＝kx＋b的解析式化为y＝k(x－m)＋n的形式，其中m，n为常数．令x＝m，则y＝n，无论k取任何不为0的实数，等式恒成立，这时该动直线恒过定点(m，n)．定点、定线、三点共线的问题将设问对调，可以互相转化. INCLUDEPICTURE"条单.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\条单.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\条单.tif" \* MERGEFORMATINET 典题训练 如图，已知直线y＝kx－2k＋3(k≠0)与抛物线y＝2相交于A，B两点(点A在点B的左侧)． (1)不论k取何值，直线y＝kx－2k＋3必经过定点P，直接写出点P的坐标； (2)已知B，C两点关于抛物线的对称轴对称，求证：直线AC必经过一定点． INCLUDEPICTURE"SK18-55.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\SK18-55.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\SK18-55.tif" \* MERGEFORMATINET INCLUDEPICTURE"标1.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标1.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标1.tif" \* MERGEFORMATINET 特训31　二次函数中的参数范围INCLUDEPICTURE"标2.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE"条单.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\条单.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\条单.tif" \* MERGEFORMATINET 方法整合 1.通过抛物线与x轴的交点问题，求二次函数的系数取值范围．2．通过抛物线与直线的交点问题，求图象上点的坐标取值范围. INCLUDEPICTURE"条单.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\条单.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\条单.tif" \* MERGEFORMATINET 典题训练 1．已知二次函数y＝x2＋2mx－4m，对满足x≥1的任意实数x，都使得y≥0成立，求实数m的取值范围． 2．已知二次函数y＝ax2＋bx＋(a＞0，b＜0)的图象与x轴只有一个公共点A，过点A的直线y＝x＋k与二次函数的图象相交于另一点B，当b≥－1时，求点B的横坐标m的取值范围． INCLUDEPICTURE"标1.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标1.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标1.tif" \* MERGEFORMATINET 特训32　二次函数的区间最值INCLUDEPICTURE"标2.tif" INCLUDEPICTURE "D:\\课件\\中考福建数学\\标2.tif" \* MERGEFORMATINET INCLUDEPICTURE "C:\\Users\\庞建宇\\Desktop\\中考数学福建\\标2.tif" \* MERGEFORMATIN ... ...