1 |
x |
∴函數(shù)f(x)的定義域為(0,+∞),
f′(x)=1-
1 |
x2 |
a |
x |
x2+ax-1 |
x2 |
設(shè)函數(shù)f(x)在點(diǎn)(x0,y0)處的切線的斜率為2,
則
| ||
|
即
x | 20 |
欲使該方程在x∈(0,+∞)內(nèi)有且僅有一根,
應(yīng)滿足
|
(Ⅱ)g(x)=3x+
1 |
x |
g′(x)=3-
1 |
x2 |
2 |
x |
3x2+2x-1 |
x2 |
1 |
3 |
g'(x)<0,解得0<x<
1 |
3 |
所以函數(shù)g(x)的單調(diào)遞增區(qū)間為(
1 |
3 |
1 |
3 |
所以函數(shù)有極小值g(
1 |
3 |