2016中考数学二轮复习-二次函数与一元二次方程的综合.pdf
1 第一讲:二次函数与一元二次方程的综合内容要求中考分值考察类型二次函数与一元二次方程综合题会根据二次函数的解析式求其图象与坐标轴的交点坐标,会确定图象的顶点、开口方向和对称轴;会利用二次函数的图象求一元二次方程的近似解7 二次函数与一元二次方程1.熟练掌握二次函数的有关知识点2.掌握二次函数与一元二次方程的联系。【例 1】在平面直角坐标系xOy 中,二次函数y=a1x2+2x+1 与 x轴有交点,a 为正整数.1求 a 的值.2将二次函数y=a1x2+2x+1 的图象向右平移m 个单位,向下平移m2+1 个单位,当2 x1时,二次函数有最小值3,求实数 m 的值.27.解:1 二次函数y=a1x2+2x+1 与 x 轴有交点,令 y=0,则 a1x2+2x+1=0,=4-4(a-1)0,解得 a2.1 分.a 为正整数.a=1、2 又y=a1x2+2x+1 是二次函数,a 10,a1,a 的值为 2.2分2 a=2,二次函数表达式为y=x2+2x+1,将二次函数y=x2+2x+1 化成顶点式y=x+12 二次函数图象向右平移m 个单位,向下平移m2+1 个单位后的表达式为y=x+1m2m2+1.此时函数的顶点坐标为m1,m21.4分当 m12,即 m 1 时,x=2 时,二次函数有最小值3,3=1m2m2+1,解得32m且符合题目要求.5分当 2 m11,即 1 m2,时,当x=m1 时,二次函数有最小值m21=3,解得2m.-2m不符合 1 m2 的条件,舍去.2m.6分当 m11,即 m2 时,当x=1 时,二次函数有最小值3,3=2m2m2+1,解得32m,不符合 m2 的条件舍去.例题精讲方法策略考试要求yx11O27 题图2 Oyx综上所述,m 的值为32或27分【例 2】已知二次函数22(1)(31)2ykxkx1二次函数的顶点在x轴上,求k的值;2假设二次函数与x轴的两个交点A、B 均为整数点坐标为整数的点,当k为整数时,求A、B 两点的坐标.23.解:1方法一 二次函数顶点在x轴上,2-4=0bac,且0a1分即22314210ak,且2-10k=3k3分2二次函数与x轴有两个交点,2-40bac,且0a分即2-30k(),且k 1当3k且1k时,即可行A、B两点均为整数点,且k为整数1222-1+-3-1+-3-42=-1-1-1+1kkkkkxkkkk(3)()342()2()2()2222-1-3-1-+3+21=-1-1-1-1kkkkkxkkkk(3)()322()2()2()5分当=0k时,可使1x,2x均为整数,当=0k时,A、B两点坐标为(-1 0),和(2 0),6分【例 3】已知:关于x 的一元二次方程x2+(m+1)x+(m+2)=0m0 1求证:该方程有两个不相等的实数根;2当抛物线y=x2+(m+1)x+(m+2)经过点 3,0,求该抛物线的表达式;3在 2的条件下,记抛物线y=x2+(m+1)x+(m+2)在第一象限之间的部分为图象G,如果直线y=k(x+1)+4 与图象 G 有公共点,请结合函数的图象,求直线 y=k(x+1)+4 与 y 轴交点的纵坐标t 的取值范围1证明:=(m+1)24(1)(m+2)=(m+3)2.1分 m 0,(m+3)20,即 0,原 方 程 有 两 个 不 相 等 的 实 数 根.2分2解:抛物线抛物线y=x2+(m+1)x+(m+2)经过点 3,0,32+3(m+1)+(m+2)=0,3分 m=1.y=x2+2 x+3.4分文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D33 3解:y=x2+2x+3=(x1)2+4,该抛物线的顶点为1,4.当直线 y=k(x+1)+4 经过顶点 1,4时,4=k(1+1)+4,k=0,y=4.此 时 直 线y=k(x+1)+4与y 轴 交 点 的 纵 坐 标 为4.5分 y=x2+2x+3,当 x=0 时,y=3,该抛物线与y 轴的交点为 0,3.此 时 直 线y=k(x+1)+4与y 轴 交 点 的 纵 坐 标 为3.6分3 t 4.7分【例 4】已知关于x 的一元二次方程04)15(22mmxmx.1求证:无论m 取何实数时,原方程总有两个实数根;2假设原方程的两个实数根一个大于3,另一个小于8,求 m 的取值范围;3抛物线mmxmxy224)15(与 x 轴交于点A、B点 A 在点 B 的左侧,现坐标系内有一矩形OCDE,如图 11,点 C0,5),D6,5),E6,0),当 m 取第 2问中符合题意的最小整数时,将此抛物线上下平移h个单位,使平移后的抛物线与矩形OCDE 有两个交点,请结合图形写出h 的取值或取值范围直接写出答案即可.解:(1)证明:=)4(14)15(22mmm1分=1692mm=2)13(m2)13(m0,2分 无论 m 取何实数时,原方程总有两个实数根.2 解关于 x 的一元二次方程04)15(22mmxmx,得14,21mxmx.3分由题意得31488143mmmm或4分解得821m.5分35h或94h.7分文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D34 逆袭训练1.已知关于x 的方程 mx2(3m1)x+2m2=0 1求证:无论m 取任何实数时,方程恒有实数根2假设关于x 的二次函数y=mx2(3m1)x+2m 2 的图象与x 轴两交点间的距离为2 时,求二次函数的表达式.解:(1)=9m26m+18m2+8m=m2+2m+1,=m+12;=m+120,.(1 分)无论 m 取任何实数时,方程恒有实数根;(2)设 x1,x2为抛物线 y=mx23m1x+2m2 与 x 轴交点的横坐标令 y=0,则 mx23m1x+2m2=0 由求根公式得,x1=2,.(2 分)抛物线 y=mx2 3m1 x+2m2不管 m为任何不为 0的实数时恒过定点2,0 x2=0或 x2=4,m=1 或)当 m=1 时,y=x22x,抛物线解析式为 y=x22x 当时,382312xxy答:抛物线解析式为y=x22x;或382312xxy.(3分)2.已知:关于x的一元二次方程22(1)20(0)axaxaa1求证:方程有两个不相等的实数根;2设方程的两个实数根分别为1x,2x 其中1x 2x 假设y是关于a的函数,且21yaxx,求这个函数的表达式;3在 2的条件下,结合函数的图象答复:假设使231ya,则自变量a的取值范围为1证明:22(1)20(0)axaxaa是关于x的一元二次方程,2 2(1)4(2)aa a 1 分=4即0 方程有两个不相等的实数根 2 分2 解:由求根公式,得2(1)22axa1x或21xa 3 分文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D35 0a,1x 2x,11x,221xa 4 分211yaxxa即1(0)yaa为所求 5分30a23 7分3.已知关于x的方程231220mxmxm 1求证:无论m取任何实数时,方程恒有实数根;2假设关于x的二次函数23122ymxmxm的图象经过坐标原点,得到抛物线1C将抛物线1C向下平移后经过点0,2A进而得到新的抛物线2C,直线l经过点A和点2,0B,求直线l和抛物线2C的解析式;3在直线l下方的抛物线2C上有一点C,求点C到直线l的距离的最大值解:1当0m时,2x当0m时,231422mmm22961 88mmmm22211mmm210m,0综上所述:无论m取任何实数时,方程恒有实数根;3分2二次函数2(31)22ymxmxm的图象经过坐标原点220m1m4 分抛物线1C的解析式为:22yxx抛物线2C的解析式为:222yxx设直线l所在函数解析式为:ykxb将A和点2,0B代入ykxb直线l所在函数解析式为:2yx 5 分3据题意:过点C作CEx轴交AB于E,可证45DECOAB,则22ECCD设2,22C t tt,,2E t t,03tECECyy23tt23924t6 分3032当32t时,max94ECCD随EC增大而增大,xyOByxEDCBAO文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D36 max928CD为所求.7 分4.已知关于x 的方程2230 xmxm1求证:方程2230 xmxm总有两个实数根;2求证:抛物线223yxmxm总过 x 轴上的一个定点;3在平面直角坐标系xOy 中,假设 2中的“定点”记作 A,抛物线223yxmxm与 x 轴的另一个交点为B,与 y 轴交于点C,且 OBC 的面积小于或等于8,求 m 的取值范围解:124bac=2243mm.1 分=244412mmm=2816mm=24m240m,方程2230 xmxm总有两个实数根.2 分221,2242mmx=242mm.3 分11x,23xm,抛物线223yxmxm总过 x 轴上的一个定点1,0.4 分3抛物线223yxmxm与 x 轴的另一个交点为B,与 y 轴交于点C,B3m,0,C0,m3,.5 分 OBC 为等腰直角三角形,OBC 的面积小于或等于8,OB,OC 小于或等于4,3m4或 m3 4,.6 分m1 或 m7 1m7 且3m.7 分5.已知关于x 的一元二次方程23(1)230mxmxm.1如果该方程有两个不相等的实数根,求m 的取值范围;xyO文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D37 2 在 1 的条件下,当关于 x 的抛物线23(1)23ymxmxm与 x 轴交点的横坐标都是整数,且4x时,求 m 的整数值解:1由题意m 0,1分 方程有两个不相等的实数根,0 2分即22 3(1)4(23)(3)0mmmm得 m 3 3分 m 的取值范围为m0 和 m 3;2设 y=0,则23(1)230mxmxm2(3)m,33(3)2mmxm123mxm,21x 5分当123mxm是整数时,可得 m=1 或 m=1 或 m=3 6分4x,m 的值为 1 或 3 7分6.已知:关于x的一元二次方程2(3)-30mxmx1求证:无论m取何值,此方程总有两个实数根;2设抛物线2(3)-3ymxmx,证明:此函数图像一定过x轴,y轴上的两个定点设x轴上的定点为点 A,y轴上的定点为点C;3设此函数的图像与x轴的另一交点为B,当 ABC 为锐角三角形时,求m的取值范围解:122(3)12(3)mmm2(3)0m无论 m 取何值,此方程总有两个实数根.2 分2由公式法:21,23(3)123(3)22mmmmmxmmx1=1,x2=m3.4分此函数图像一定过x轴,y轴上的两个定点,分别为A 1,0,C0,34 分3由 2可知抛物线开口向上,且过点A 1,0,C0,3和 Bm3,0.观察图象,当m0 时,ABC 为钝角三角形,不符合题意.-3CBA3xy63-10文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U9O6O5U2 HS4A8M5X9B7 ZP4Y9A8L2D3文档编码:CS7U