内容正文:
拓展与延伸8
隐零点
啦
BIN
)
做
元
e
2
只
)
越
布
艺
艺
雄
坐
趨
糊
4日
4日
1
越
C古
以
拉
艺
以
:1
域
(x-1)
①
区
f(x)
h(x)=f(x)-g(x)
h(x)
f(x)xe*-1,g(x)=Inx-mx,meR
f(x)
f'(x>0
f(x)
f(x)
f(-1
R,f'(x)=(x+le
(-00,-1
1-1
e
x<-1f'(x<0
x>-1
(-1,+o0)
h(x)=xe*-Inx+mx-1
x∈(0,+o)h(x)=0
e-lnx+
+m=0
k(x=e'-
+1+m
Inx+
h(x)k(x
k'(x)=e_1-(nx+e'+Inx
x2
X
川刘=xe+nx刘=x+2x小c+
x>0
r(x>0
r(x)
(0,+0)
8.2-1nme0
r(x)=0
x∈(0,x)r(x)<0k'(x<0
k(x)
(0
,
+m
Xo
r(x)=0
p(x)=f(x)+1p(x)
(0,+o)
ix
xo =-Inxo
Inxo
x∈(x,+o)r>0k(x>0
(,+0
k(x)
xe*+Inxo =0
e
o
1
上<x<1
ln->0
e
Xo
1
eo-
=一X0
Xo
k(x)
(x)=e*
m=-1
k(x)
十00
X
+00
m>-1 h(x)
h(x)
Inxo +1
+m=m+1
Xo
m<-1
ko
k(刘
+00
m=-1 h(x
m>-1 k(x)
<0
X
k()
k(x)
m<-1
a≥1,f(x
x2x<62)
g(Inx)=g(Inx2)=0
f(x)=e'-Inx-a g(x)=e"-In(x+a)
f(x)
X
f(x)=e*
f'(x(0,+o
1x>0)
M=fx刘=e-x>0j
1-c->0
J3--2<0fi=-10
g
f=0
e=1
x∈0,x)
Xo
f'(x)<0x∈(x,+∞)f'(x>0
f(x)
f(x)min =f(xo)=e-Inxo-a=x0+
x→0,f(x)→+o0
f(x)
x
Xo
(0,x
(0,+00
1-a
x→+0,f(x→+o
Xo
fx)<0
y
x+-a<0
Xo
a
fx)=f(x)=0
a=e
g(Inx)=x-In(Inx+e-Inx)==0
g(Inx)=g(Inx2)=0
-Inx et -Inx2
g(1nx)=0
f(x)
m>0
g(x)=f(x
f(x)=e*-
-m(x-1)
-Inx
0
1<x,<2
f=e-l,f"x刘=e-
X
x>0
1(x)f(x)
…f'1
xE(1,+oo)f(x)>0,f(x)
(1,+00
10=e1-1
X
00=e>0
=0
x∈(0,1f'(x)<0,f(x
..f(x)
(0,1)
g(x)=f(x)-m(x-1)=e*
g(x=e1-1-m(x>0,m>0)
X
1m-m-m-0
1+m
g(t)=0
x∈(0,1g'()<0,gx
.'.g(x)min =g(t)=e-Int-mt+m
-Inx-mx+m(m >
g(x)(0,+oo)
8'(1)=-m<0
t∈(1,1+m)c(1,+o)
x∈(t,+oo)g(t)>0,gx)
g(x)=e-Inx-mx+m=0
为6=1>180=e}m-0
m
g(t)=e'--Int-mt+m=0
2-je1-lr+1-0t>0l0=2-e1-r+1->
-1-ne-+-e+k0ei1+
h=1>0,a21=}2<0
h(t)=0t∈(1,2)1<<2
y=f(x)y=g(x)
m,n
':y=s0<s<1
A(x1,y),B(x2,2),C(3,y3)
S
f(x)=e
y=f(x)
X1<X2<X3
g(x)=In(x+n)
l:y=x+m
y=g(x)
X1,X2,X3
y=x+m y=f(x)
t=0f(t)=e°=1
(0,1
m
(P,8(p))
g(0=g(p)=1
x+n
p+n
n=2
m=1n=2
(t,/(D))
f(x)=e*
f'(t)=e'=1
1
1:y=x+1y=x+1y=g(x)
=1
p+n=1
(p,0)p=-1
e=x2+1=lh(x3+2)=s
X1,X2,X3
2x2=X1+X3
2s
h(s)=lns+e-2s(0<s<1)
h(s)=2+e
S
o'(s)(0,1
3s,e5》
e0:
p'(s)=0
x=Ins x2=s-1 x3=e*-2
2=Ins+e5-2 Ins+e5-2s=0
-2
p(s)=+e-2
S
34e<0
p'(1)=-1+e>0
s∈(0,5)
p'(s)<0
s∈s,1
0a。
p(s)>0
h(s>0
h(s)
h(1)=e-2>0
h()(c3,1
p'(s)>0p(s)(0,)
(s0,1
5?2x》。g
1e0,2)
So
00
So
(0,1)
h(e)=-3+ee-2e3<0
S