| a+2 | a+2 | |||
proszę o udowodnienie nierownosci (nie można uzywac tezy !) | + | >bądź rowne 4 | ||
| a | 2 |
| a+2 | a+2 | 2 | a | 2 | a | ||||||
+ | = 1+ | + | +1= 2+ | + | |||||||
| a | 2 | a | 2 | a | 2 |
| |||||||||||||
≥√2a*a2= 1 /*2 | |||||||||||||
| 2 |
| 2 | a | |||
to: | + | ≥2 | ||
| a | 2 |
| 2 | a | |||
zatem 2+ | + | ≥ 2+2= 4 | ||
| a | 2 |
| 2 | a | |||
√ | * | |||
| a | 2 |
myślałam,że tyle to wiesz ?
| a+b | |
≥ √ab | |
| 2 |
| a | 2 | |||
Przyjmując w tym zadaniu a = | oraz b = | dostajesz to co Eta napisała | ||
| 2 | a |
nieco inaczej np. tak :
| a | 2 | |||
(a−2)2 ≥0 ⇔ a2−4a+4 ≥ 0 ⇔ a2+4 ≥ 4a / :2a>0 ⇔ | + | ≥ 2 /+2 ⇔ | ||
| 2 | a |
| a | 2 | a | 2 | |||||
⇔ | + | +2 ≥ 4 ⇔ | +1+ | +1 ≥ 4 ⇔ | ||||
| 2 | a | 2 | a |
| a | 2 | 2 | a | a+2 | 2+a | |||||||
⇔ | + | + | + | ≥ 4 ⇔ | + | ≥ 4 . c.n.u. ![]() | ||||||
| 2 | 2 | a | a | 2 | a |