2
1
y D ax 2 C bx C
2
xD3
y
xD1
y
3
a
2
(i) (ii)
2
a b
(i) (ii)
a b
8
ˆ
<
AB
bD
ˆ
:
C
Da C b C
a
D
a
2
E
a2 C
aD
F
HI
K
1
a
bD
G
J
D0
2
2
P D 2x 2
x C 2 Q D x2
E D P2
ED P
*1
L
Q
Á
M
PC
Q
N
Á
x
ED
xD
3P C 6Q
*1
E
E
4Q2
2x C 1
1
3
p
5
p
5
E
O
S
Á
P
x x
C
factorize
2
T
Q
q
U
x
R
Á
1
*2 OABC
1
3 1
LM
L,
t .t
OA
BC
*3
1/
O
M
P
0
C
L
M
A
B
!
!
!
OA D aE OB D bE OC D cE
!
OP
!
OP D
aE
A
Á
bE C cE D
bE C cE
!
OP
Á
Á
t aE C
C
B
bE C cE
F
!
OP D
aE
aE bE cE
q
1
H
aE
bE C cE
2
t2
I
Á
*4
t
L
tD
q
!
OP
cos †AOP D
*2
*3
*4
D
P
M
N
O
q
Q
R
regular tetrahedron
divide internally
inner product
3
D
E
t bE C cE
G
J
tC
K
Á
a>0
x
2
2
2
sin 2x C a cos x D 0
aD
p
cos 2x C a sin x D
2
x
xD
AB
C
DE
x
aD
2
p
2
a
sin x D
aD
q
FG
H
x
a cos 2x D
a2 D
K
K
xD
LK
N
4
I
a2
J
1
a>0
2
C1 y D e 6x
C2 y D ax 2
C1
C1
C2
a
2
t ; e 6t
C1
e 6t x
A
yD
e 6t
C2
B
C
t
Á
2
ax 2 D
A
e 6t x
e 6t
B
C
t
Á
a t
D
e 12t
ae 6t
f .t/
E
C2
2
2
f 0 .t/ D
108e 6t
G
E
t
F
t
a
I
a>
et
D1
t!1 t
lim
derivative
5
D0
F
t
*5
f .t/
*5
Á
e 6t
C1
2
s D f .t/
F
t
D
aD
sDa
E
e
J
H
Á2
Á
K
2
0 9
Z
a t
x
2
yD
x
1
.x
t2
y
D
V1
D
a
at 2 /2
y
D
x
1
V2
1
t
V1 D V2
V1
Z
V1 D
L
K
D
1
t
M
a
P
at 2 /
.x
t
N
dx
Q
O
V2
Z
V2 D
Y
S
T
p Á
y
U
dy
K
a
D
aD
R
W
t
X
V
t
V1 D V2
Z
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 t
8 at 2
9 a2 t 2
6