2010年中考数学压轴题100题精选(1-10题)答案
时间:2025-07-09
时间:2025-07-09
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2010年中考数学压轴题100题精选(1-10题)答案
【001】解:(1)
抛物线y a(x 1)2 a 0)经过点A( 2,0),
3
0 9a a ························································································· 1分
二次函数的解析式为:y
3
x
2
3
x
3
·················································· 3分
(2)
D为抛物线的顶点 D(1过D作DN OB于N
,则DN ,
AN 3, AD
OM∥AD
·················································· 4分 6 DAO 60° ·
①当AD OP时,四边形DAOP是平行四边形
··············································· 5分 OP 6 t 6(s) ·
②当DP OM时,四边形DAOP是直角梯形
过O作OH AD于H,AO 2,则AH 1
(如果没求出 DAO 60°可由Rt△OHA∽Rt△DNA求
AH··························································································· 6分 OP DH 5t 5(s) ·
③当PD OA时,四边形DAOP是等腰梯形 OP AD 2AH 6 2 4 t 4(s)
综上所述:当t 6、5、4时,对应四边形分别是平行四边形、直角梯形、等腰梯形. · 7分
△OCB是等边三角形 (3)由(2)及已知, COB 60°,OC OB,
则OB OC AD 6,OP t,BQ 2t, OQ 6 2t(0 t 3)
2
过P作PE OQ于E,则PE ········································································· 8分
2
SBCPQ
32
3 6 (6 2t) t
2 2 222
11 ································ 9分
当t
时,SBCPQ32
34
···································································10分
此时OQ 3,OP=,OE QE 3
34
94
PE
4
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PQ
·····················
······11分 2【
002】解:(1)1,;
5
8
(2)作QF⊥AC于点F
,如图3, AQ = CP= t,∴AP
由△AQF∽△ABC,BC 4,
3 t
.
得
QF4
t525
.∴QF
t
2
45
t
. ∴S
12
(3 t)
45
t
图3
P
即S
65
t
.
(3)能.
①当DE∥QB时,如图4.
图4
∵DE⊥PQ,∴PQ⊥QB,四边形QBED是直角梯形. 此时∠AQP=90°. 由△APQ ∽△ABC,得即
t3 3 t5
AQAC
APAB
,
. 解得t
98
.
②如图5,当PQ∥BC时,DE⊥BC,四边形QBED是直角梯形. 此时∠APQ =90°. 由△AQP ∽△ABC,得 即
t5 3 t3
AQAB
APAC
图5
,
. 解得t或t
4514
158
.
(4)t
52
.
【注:①点P由C向A运动,DE经过点C. 方法一、连接QC,作QG⊥BC于点G,如图6.
PC t
,QC
QC
2
QG CG [(5 t)] [4 (5 t)]
55
22
3
2
4
2
.
52
由PC2
2
,得t2
3422
[(5 t)] [4 (5 t)]55
,解得t.
方法二、由CQ
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