Răspunsuri

2014-09-27T14:28:22+03:00
Folosesti inegaliatatea mediilor : m.a.≥m.g. ⇒ a+b/2≥√ab.
 x+1/2≥√x ⇒      x+1≥2√x
 y+1/2≥√v ⇒      y+1≥2√y, facem produsul relatiilor
                   (x+1)(y+1)≥4√xy, dar cum xy =1 ⇒ (x+1)(y+1)≥4.
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