摘要: 解:原式························································································ 2分 ·········································································································· 5分 ···················································································································· 6分
网址:http://m.1010jiajiao.com/timu_id_4440474[举报]
解:(1)点C的坐标为.
∵ 点A、B的坐标分别为,
∴ 可设过A、B、C三点的抛物线的解析式为.
将代入抛物线的解析式,得.
∴ 过A、B、C三点的抛物线的解析式为.
(2)可得抛物线的对称轴为,顶点D的坐标为
,设抛物线的对称轴与x轴的交点为G.
直线BC的解析式为.
设点P的坐标为.
解法一:如图8,作OP∥AD交直线BC于点P,
连结AP,作PM⊥x轴于点M.
∵ OP∥AD,
∴ ∠POM=∠GAD,tan∠POM=tan∠GAD.
∴ ,即.
解得. 经检验是原方程的解.
此时点P的坐标为.
但此时,OM<GA.
∵
∴ OP<AD,即四边形的对边OP与AD平行但不相等,
∴ 直线BC上不存在符合条件的点P. - - - - - - - - - - - - - - - - - - - - - 6分
解法二:如图9,取OA的中点E,作点D关于点E的对称点P,作PN⊥x轴于
点N. 则∠PEO=∠DEA,PE=DE.
可得△PEN≌△DEG .
由,可得E点的坐标为.
NE=EG=, ON=OE-NE=,NP=DG=.
∴ 点P的坐标为.∵ x=时,,
∴ 点P不在直线BC上.
∴ 直线BC上不存在符合条件的点P .
(3)的取值范围是.
查看习题详情和答案>>解分式方程
+
=
,下列四步中,错误的一步是( )
2 |
x+1 |
3 |
x-1 |
6 |
x2-1 |
A、方程两边分式的最简公分母是x2-1 |
B、方程两边都乘以(x2-1),得整式方程2(x-1)+3(x+1)=6 |
C、解这个整式方程得:x=1 |
D、原方程的解为x=1 |
解分式方程
+
=
,下列四步中,错误的一步是( )
查看习题详情和答案>>
2 |
x+1 |
3 |
x-1 |
6 |
x2-1 |
A.方程两边分式的最简公分母是x2-1 |
B.方程两边都乘以(x2-1),得整式方程2(x-1)+3(x+1)=6 |
C.解这个整式方程得:x=1 |
D.原方程的解为x=1 |