题干
若f（x）是幂函数，且满足
=2，则f（
）=____．
| f |
| ( |
| 9 |
| ) |
| f |
| ( |
| 3 |
| ) |
| 1 |
| 9 |
答案(点此获取答案解析）
| 1 |
| 4 |
