题干
已知f（x）≠0，且对于任意的实数a，b有f（a+b）=f（a）f（b），又f（1）=2，则
+
+
+⋯+
+
=____．
| f |
| ( |
| 2 |
| ) |
| f |
| ( |
| 1 |
| ) |
| f |
| ( |
| 4 |
| ) |
| f |
| ( |
| 3 |
| ) |
| f |
| ( |
| 6 |
| ) |
| f |
| ( |
| 5 |
| ) |
| f |
| ( |
| ) |
| f |
| ( |
| ) |
| f |
| ( |
| ) |
| f |
| ( |
| ) |
答案(点此获取答案解析）
2018
