Given a, b, c as real numbers such that a2 + b2 + c2 = 1
Prove that 2(1 + a)(1 + b)(1 + c) ≥ abc
№ | Пользователь | Рейтинг |
---|---|---|
1 | tourist | 3690 |
2 | jiangly | 3647 |
3 | Benq | 3581 |
4 | orzdevinwang | 3570 |
5 | Geothermal | 3569 |
5 | cnnfls_csy | 3569 |
7 | Radewoosh | 3509 |
8 | ecnerwala | 3486 |
9 | jqdai0815 | 3474 |
10 | gyh20 | 3447 |
Страны | Города | Организации | Всё → |
№ | Пользователь | Вклад |
---|---|---|
1 | maomao90 | 174 |
2 | awoo | 165 |
3 | adamant | 162 |
4 | TheScrasse | 160 |
5 | nor | 158 |
6 | maroonrk | 156 |
7 | -is-this-fft- | 152 |
8 | orz | 146 |
9 | SecondThread | 145 |
9 | pajenegod | 145 |
Название |
---|
Auto comment: topic has been updated by cheater2k (previous revision, new revision, compare).
may be missing some conditions ? I got abc > = 2√3 - 1 which is wrong ofcourse
Cauchy inequality?
I can't understand the relation between codeforces and proving an equality????
Someone has answered the question over here
I'll write the answer here again -
You can consider the sign of abc. If abc≥0, then the required result follows. If abc < 0, it suffices to show that (1 + a)(1 + b)(1 + c)≥0.