题干
已知函数f（x）= {x−
,(x＞
) x2 +2x+a−1,(x≤
)
| 2 |
| x |
| 1 |
| 2 |
| 1 |
| 2 |
答案(点此获取答案解析）
解：①x＞
时，f（x）=0，即x﹣
=0，解得x=
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| 2 |
| 2 |
| x |
