1 |
2-x-1 |
1 |
2 |
1 | ||
|
1 |
2 |
=-(
2x |
1-2x |
1 |
2 |
2x |
2x-1 |
1 |
2 |
1 |
2x-1 |
1 |
2 |
1 |
2x-1 |
1 |
2 |
∴f(x)是偶函數(shù).
(2)當(dāng)0<x<
π |
2 |
當(dāng)-
π |
2 |
∵f(x)為偶函數(shù),由上式知f(x)>0,故f(x)>0成立.
綜上可得,f(x)>0.
1 |
2x-1 |
1 |
2 |
π |
2 |
π |
2 |
1 |
2-x-1 |
1 |
2 |
1 | ||
|
1 |
2 |
2x |
1-2x |
1 |
2 |
2x |
2x-1 |
1 |
2 |
1 |
2x-1 |
1 |
2 |
1 |
2x-1 |
1 |
2 |
π |
2 |
π |
2 |