文档内容
2024 届高三定时训练
(
3
−
6
2
9
,
a
0 ]
= 4 A = { x | 5 x 7 }
3
2
e
B={x|x3 x5}
A B = { x | 5 x 7 }
a2 2a−1a+1 A = A B
a 2 2a−1a+1 A
2a−13
A B
a2
a
a
+
1
2
5
a=2 a4
{#{QQABaYCAggCAAAIAAAhCUwXSCkGQkBCCAKoGBEAIoAABQANABAA=}#}a
f ( x ) = ( x − 3 ) ( x − a )
a | a 2 a 4
f ( x
a
a
a
) =
=
(
3
3
3
x − 3 ) ( x − a )
f
f
f
(
(
(
x
x
x
)
)
)
0
0
0
(
(
a
3
,
,
3
a
)
)
x [ 4 , + ) f ( x ) − 9 a x +
x
9
− 3
9 9 9
x+ = x−3+ +32 (x−3) +3=9
x−3 x−3 x−3
x − 3 =
x
9
− 3
x = 6
a9
a {a|a9}
f(x)= 3sin2x+cos2x+1
= 2 (
2
3
s i n 2 x +
1
2
c o s 2 x ) + 1
π
=2sin(2x+ )+1
6
{#{QQABaYCAggCAAAIAAAhCUwXSCkGQkBCCAKoGBEAIoAABQANABAA=}#}2 k π
k π
+
+
π
2
π
6
2 x
x
+
π
6
k π
+
2
2
k π
π
3
+
3 π
2
k Z
k Z
π 2π
[kπ+ ,kπ+ ] kZ
6 3
f(A)=2,
A
a
=
(
2
0 , π
3
)
s i n (
2
2
A
A
+
+
π
6
π
6
=
) =
5 π
6
1
2
A =
π
3
a2 =b2+c2−2bccosA b2+c2−bc=12
b c = b 2 + c 2 − 1 2 2 b c − 1 2 b c 1 2
b=c=2 3
S
△
=
A
1
2
B
b
C
c s i n A =
4
3
b c 3 3
3 3
f ( x ) R x0 f ( x ) = x 2 e x
x0时 −x0
f (
f
x
(
)
x
=
) =
−
x
−
x
2 e
f ( − x )
2 − x e , x
x , x
=
− [
0
0
( − x ) 2 e − x ] = − x 2 e − x
f(x) R
f(ax2 −3x−1)+ax2 −3x−1− f(5−ax)+ax−5
{#{QQABaYCAggCAAAIAAAhCUwXSCkGQkBCCAKoGBEAIoAABQANABAA=}#}xR
f ( a x 2 − 3 x − 1 ) + a x 2 − 3 x − 1 f ( a x − 5 ) + a x − 5 x R
h(x)= f(x)+x h(x) R
a
a
x
2 −
0
( 3 + a ) x + 4 0
a x 2 − 3 x −
x
1
R
a x − 5 x R
a0 ( 3 + a ) 2 − 1 6 a 0 1a9
a
n = 1
(1 , 9 )
2a2 =a2 +2
1 1
n 2
a
1
= 2
2a S =a2 +2n,
n n n
可得 2 S
n
( S
n
− S
n − 1
) = ( S
n
− S
n − 1
) 2 + 2 n
S 2n − S 2n
− 1
= 2 n
S2 =S2 +(S2 −S2)+(S2 −S2)+ +(S2 −S2 )=n2 +n
n 1 2 1 3 2 n n+1
S = n2 +n = n(n+1)
n
a =S −S = n(n+1)− (n−1)n ............................................ 5分
n n n−1
a = 2
1
{#{QQABaYCAggCAAAIAAAhCUwXSCkGQkBCCAKoGBEAIoAABQANABAA=}#}a
n + 1
a
=
n
=
( n
n
+
(
1
n
) (
+
n
1
+
) −
2 ) −
( n −
n
1
( n
) n
+ 1 )
故 a
n + 1
− a
n
=
2
n +
n
2
+
+
1
n
−
n +
2
1 +
n
n − 1
=
2 n + 1 (
(
n
n
+
+
1
2
+
+
n
n
−
) (
1 )
n
−
+
2
1 +
n (
n
n
−
+
1
2
)
+ n )
2(n+1)+2 n2 −1−2 n2 +2n−2n
=
( n+2+ n)( n+1+ n−1)
2(1+ n2 −1)−2 n2 +2n
= ............................................... 8分
( n+2+ n)( n+1+ n−1)
1 +
( 1 +
n 2
n
−
2
1
−
1 ) 2
n
=
2
n
+
2
2
+
n
2 n 2 − 1 n 2 + 2 n = ( n 2 + 2 n ) 2
a −a 0
n+1 n
a
a
n
1
2
2
2
2
−
−
m
m
a
n
m
f
( x )
2
1
(0,+) f(x)= +m
x
m 0 f ( x ) 0 f(x)
1
m0 x(0,− ) f(x)0 f(x)
m
{#{QQABaYCAggCAAAIAAAhCUwXSCkGQkBCCAKoGBEAIoAABQANABAA=}#}m
x
=
=
−
−
1
1
m
x ( −
1
m
f
, +
( x )
) f ( x )
l n
( −
0
1
m
) = 0
f ( x )
x
m
(
+
x
1
)
e
e
x
x
−
l n
l n
x
x
x
x
+
f
1
1
( x )
(
0 ,
g
+
(
x )
)
= −
+ x2ex +lnx
(x)=
x2
q ( x ) = x 2 e x + l n x
1
q(x)=(x2+2x)ex + 0
x
q(x)
q
x
(
0
x
e
)
x0 = −
l n
x
x
0
0 =
x
−
0
l n x
0
x
e
x 2 e 0
0
− ln x0
+ l
q
n
(
x
1
2
0
)
=
0
0 q (1 ) 0
h(x)= xex h(x )=h(−lnx )
0 0
h ( x ) = x e x ( 0 , + ) x =−lnx
0 0
( x )
( x ) (
(
x
0
0
,
)
x
0
)
e x0
l n x
x
0
0
1 1
x
(
0
x
0
, +
x
0
x
0
)
1
1
m
= −
+
= +
−
=
(−,0]
{#{QQABaYCAggCAAAIAAAhCUwXSCkGQkBCCAKoGBEAIoAABQANABAA=}#}