O inegalitate un pic mai dificila ...

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Virgil Nicula
Euler
Posts: 622
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O inegalitate un pic mai dificila ...

Post by Virgil Nicula »

Sa se arate ca daca \( a\ ,\ b\ ,\ c \) sunt pozitive si \( a+b+c=1 \) , atunci \( 4(ab + bc + ca)\ \le\ 1 + 9abc\ . \)
Marius Mainea
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Location: Gaesti (Dambovita)

Re: O inegalitate un pic mai dificila ...

Post by Marius Mainea »

Virgil Nicula wrote:Sa se arate ca daca \( a\ ,\ b\ ,\ c \) sunt pozitive si \( a+b+c=1 \) , atunci \( 4(ab + bc + ca)\ \le\ 1 + 9abc\ . \)
Se foloseste inegalitatea lui Schurr

\( 4(xy+yz+zx)(x+y+z)-9xyz\le (x+y+z)^3 \) pentru \( x,y,z\ge 0 \)
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