f'(x)=4x-3-
1 |
x |
(4x+1)(x-1) |
x |
∴当x∈(
1 |
e |
即f(x)在(
1 |
e |
∵f(1)=-1<0,f(
1 |
e |
(e-1)(e-2) |
e2 |
∴函数f(x)在区间(
1 |
e |
( II)∵a≠0f′(x)=
(2ax+1)(x-1) |
x |
∴f'(x)=0的根是1 , -
1 |
2a |
当-
1 |
2a |
∴函数f(x)在(1,e)上单调,
故a>0 或a≤-
1 |
2 |
当-
1 |
2a |
1 |
2a |
1 |
2e |
综上a≤-
1 |
2 |
1 |
2e |
1 |
e |
1 |
x |
(4x+1)(x-1) |
x |
1 |
e |
1 |
e |
1 |
e |
(e-1)(e-2) |
e2 |
1 |
e |
(2ax+1)(x-1) |
x |
1 |
2a |
1 |
2a |
1 |
2 |
1 |
2a |
1 |
2a |
1 |
2e |
1 |
2 |
1 |
2e |