涓撻灞傜骇蹇粌
(
鍗佸叓
)
1
锛?/p>
(2019路
娌冲寳淇濆畾妯℃嫙
)
宸茬煡
f(x)
锛?/p>
lnx
x
锛屽垯
(
)
A
锛?/p>
f(2)>f(e)>f(3)
B
锛?/p>
f(3)>f(e)>f(2)
C
锛?/p>
f(3)>f(2)>f(e)
D
锛?/p>
f(e)>f(3)>f(2)
绛旀
D
瑙ｆ瀽
f(x)
鐨勫畾涔夊煙鏄?/p>
(0
锛?/p>
锛?/p>
鈭?/p>
)
锛?/p>
f
鈥?/p>
(x)
锛?/p>
1
锛?/p>
lnx
x
2
锛?/p>
浠?/p>
f鈥?x)
锛?/p>
0
锛?/p>
寰?/p>
x
锛?/p>
e.
鎵�浠ュ綋
x
鈭?/p>
(0
锛?/p>
e)
鏃讹紝
f
鈥?/p>
(x)>0
锛?
f(x)
鍗曡皟閫掑锛屽綋
x
鈭?/p>
(e
锛岋紜
鈭?/p>
)
鏃讹紝
f
鈥?/p>
(x)<0
锛?/p>
f(x)
鍗曡皟閫掑噺锛屾晠
x
锛?/p>
e
鏃讹紝
f(x)
max
锛?/p>
f(e)
锛?/p>
1
e
锛岃�?/p>
f(2)
锛?
ln2
2
锛?/p>
ln8
6
锛?/p>
f(3)
锛?/p>
ln3
3
锛?/p>
ln9
6
锛屾墍浠?/p>
f(e)>f(3)>f(2)
锛庢晠閫?/p>
D.
2
锛庤嫢
0<x
1
<x
2
<1
锛屽垯
(
)
A
锛?/p>
ex
2
锛?/p>
ex
1
>lnx
2
锛?/p>
lnx
1
B
锛?/p>
ex
2
锛?/p>
ex
1
<lnx
2
锛?/p>
lnx
1
C
锛?/p>
x
2
ex
1
>x
1
ex
2
D
锛?/p>
x
2
ex
1
<x
1
ex
2
绛旀
C
瑙ｆ瀽
浠?/p>
f(x)
锛?/p>
e
x
x
锛屽垯
f鈥?x
)
锛?/p>
xe
x
锛?/p>
e
x
x
2
锛?/p>
e
x
锛?/p>
x
锛?/p>
1
锛?/p>
x
2
.
褰?/p>
0<x<1
鏃讹紝
f
鈥?/p>
(x)<0
锛屽嵆
f(x)
鍦?/p>
(0
锛?/p>
1)
涓婂崟璋冮�掑噺锛屽洜涓?/p>
0<x
1
<x
2
<1
锛?/p>
鎵�浠?/p>
f(x
2
)<f(x
1
)
锛屽嵆
ex
2
x
2
<
ex
1
x
1
锛屾墍浠?/p>
x
2
ex
1
>x
1
ex
2
锛屾晠閫?/p>
C.
3
锛?/p>
(2019路
灞变笢甯堝ぇ闄勪腑妯℃嫙
)
璁惧嚱鏁?/p>
f(x)
锛?/p>
e
2x
锛?/p>
alnx.
(1)
璁ㄨ
f(x)
鐨勫鍑芥暟
f鈥?x)
闆剁偣鐨勪釜鏁帮紱
(2)
璇佹槑锛氬綋
a>0
鏃讹紝
f(x)
鈮?/p>
2a
锛?/p>
aln
2
a
.
绛旀
(1)a>0
鏃讹紝
f
鈥?/p>
(x)
瀛樺湪鍞竴闆剁偣
(2)
璇佹槑鐣?/p>
瑙ｆ瀽
(1)f(x)
鐨勫畾涔夊煙涓?/p>
(0
锛岋紜
鈭?/p>
)
锛?/p>
f
鈥?/p>
(x)
锛?/p>
2e
2x
锛?/p>
a
x
(x>0)
锛?/p>
褰?/p>
a
鈮?/p>
0
鏃讹紝
f
鈥?/p>
(x)>0
锛?/p>
f
鈥?/p>
(x)
娌℃湁闆剁偣锛?/p>
褰?/p>
a>0
鏃讹紝璁?/p>
u(x)
锛?/p>
e
2x
锛?/p>
v(x)
锛濓紞
a
x
锛?/p>
鍥犱负
u(x)
锛?/p>
e
2x
鍦?/p>
(0
锛岋紜
鈭?/p>
)
涓婂崟璋冮�掑锛?/p>
v(x)
锛濓紞
a
x
鍦?/p>
(0
锛岋紜
鈭?/p>
)
涓婂崟璋冮�掑锛?/p>
鎵�浠?/p>
f鈥?x)
鍦?/p>
(0
锛岋紜
鈭?/p>
)
涓婂崟璋冮�掑锛?/p>
鍙?/p>
f鈥?a)>0
锛屽綋
b
婊¤冻
0
锛?/p>
b
锛?/p>
a
4
涓?/p>
b
锛?/p>
1
4
鏃讹紝
f
鈥?/p>
(b)
锛?/p>
0
锛?/p>
鏁呭綋
a>0
鏃讹紝
f
鈥?/p>
(x)
瀛樺湪鍞竴闆剁偣锛?/p>
(2)
璇佹槑锛氱敱
(1)
锛屽彲璁?/p>
f鈥?x)
鍦?/p>
(0
锛岋紜
鈭?/p>
)
涓婄殑鍞竴闆剁偣涓?/p>
x
0
锛屽綋
x
鈭?/p>
(0
锛?/p>
x
0
)
鏃讹紝
f
鈥?/p>
(x)
锛?/p>
0
锛?/p>