2019年黄冈密卷数学试题

B
G
A
x
3
8.
()
1
B. [ 6
1
D.
4
Rt ACB
D AB
DE
ACB=900 B=600 AC P DF
5
1 62
2
2
2
Rt EDF C. EDF
EDF=900 D
E=450
(00
600) DE AC
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M DF BC
PM
N
CN
()
A. 3
3
B.
2
3
C.
3
1
D.
2 []
(
9.
a=
.
3
24 )
x2+(a+3)x+2a+3=0
x2-6x-4n2-32n=0
PMQ
.
n
18.(6 ) -1 x 2
y=2x2-4ax+a2+2a+2
2a
19.(8 ) 1 2.1
BC 0.2 sin40 0.645 cos40 0.766 sin25
2
AB
AD
CE
0.01
0.423 cos25 0.906,tan25
0.466
20.(10 )
D 37 M BC
N
MN
.
13
14
16
14.
AC=BC=6cm P
B
QB
BC
PQC QC
P
,Q
t
.
15.
y 1 (x2 100x 196 | x2 100x 196 |)
2
100
.
A
AB
1cm
t
2 cm
C
x 123
100
16.
M
AOB AB
OM= 2
AOB=45
OA
P OB
Q
PMQ
72
17.(6 )
x1
x2 |x1| |x2|
29 3
10. x=
2
11.
A
x4+5x3-3x2-8x+9
:1 2
100;B
:12 22
y x+y
B
x
.
. 1002. A
A
x
B
12. a7
13. ABCD AD
AB=2 a2 576 BC= a 2 14a 625 AC= a2 -14a 625
.
BC AD BC 1000 AD 2010 A 53
x2+(m-5)x+7=0
. (a2+ma+7)(b2+mb+7)=( ).
A.365
B.245
C.210
D.175 []
5.
C
BC=4
AB AC
.
()
( ).
23
A.
32
5
C.
3
6
6. 1 2
8. k
A.5
7.
53
5 23
B.
63
2
D.
3
3
13
k
( ).
B.6
C.7
4
k D.8 1
1
A.
12 1
C.
2019
120
120
(
3
42 )
1. 3 2 3 6 x y z x y z
. xyz=( ).
3
5
7
13
A.
B.
C.
D.
4
6
12
18
2.
f(x)=ax2+ax+1
f(f(1))=f(3). 2a
A.-3
B.-5 C.-7
D.-9
3. |xy|+|x+y|=1
( ).
A.2
B.4
C.6
D.8
4.a b
.
A1
20 10 2 .
23.(10 )
M
AC MD
CD
P
ABCD E BD MC MC MD
FP .
AC BD
N
EF
. :P
24.(12 )
xy
OB
ODE OD CB
1k
G
2
FG
OABC
B
. OAB O
k
F
y (x 0)
x
BFG
3
OA
P
PFG
(4 2) OA OC By F AB G
P
y
E D
CF O
A2
105
A1
22.(10 )
a
b
c
.
.
sin A sin B sin C
.
A=450, B=300 a=6 b.
a
b
,
sin A sin B
a sin B
b=
sin A
6 sin 300 sin 450
1 6
2 2 2
3 2.
30 2
1050
B1
A2
(1)
A1 A2 B2
(2)
B1
15
120
B2
ABC AC
AC O
1 AC
O
2
BC E O OD BC O D
AE AD DC
1
D AE
2
DAO = B + BAD
3
S CEF 1
S OCD 2
AC=4 CF .
21.(10 ) EF AD P
ABCD AD AB E BC F AC EF 2AE2
O, P
AC
AF CE
AC
B2
C
15
B1
120