2. 6
ˆ
BEC 40
ˆ
xAB 80
04
( xy ) //( BE )
ˆ
CBE
1
ˆ
BCE
ˆ
CEt 60
D
Ay
Et
2
( Et ) //( AB )
ˆ
A DE
3
3. 12
2009
7
01
87 11 7
11
4
01
10000 10
10
7
10
1108
608
()
3cm
ˆ
yO z
ˆ
xO y
70
110
3
3cm
ˆ
xOy 70
ˆ
yO z
4
2
598
( )
3cm
10
1
254 x 852
x
3cm
5
3
4
20
5
02
1
d 17
0
c 1
27
b2
5
a 25 10 (7 5) 145
2
z 81 3
7
7
x 49
y 5 5
4
y
x
03
A 2(5 x y ) x 9 y
A 11x 11y
1
4. x y 100
A
7
ˆ
xO y
OA
A
( )
OA 3cm
2
04
1
Ox
A
( )
(Oy )
ˆ
AOE 40
( )
E
2
ˆ
yO E
(OE )
A
E
( )
ˆ
EOF
(OF )
3
( )
(OE )
ˆ
AOF 40
H
A
4
F
Ox
K
AH AK