parte intreaga

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Adriana Nistor
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parte intreaga

Post by Adriana Nistor »

Determinati numerele naturale nenule \( p, q, r \) pentru care
\( [\frac{n}{p}]+[\frac{n+1}{q}]+[\frac{n+2}{r}]=n \)
pentru orice \( n \) numar natural.
Marius Burtea
Marius Mainea
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Re: parte intreaga

Post by Marius Mainea »

Adriana Nistor wrote:Determinati numerele naturale nenule \( p, q, r \) pentru care
\( [\frac{n}{p}]+[\frac{n+1}{q}]+[\frac{n+2}{r}]=n \)
pentru orice \( n \) numar natural.
Marius Burtea
Luind n=pqr obtinem ecuatia \( \frac{1}{p}+\frac{1}{q}+\frac{1}{r}=1 \) de unde

\( \{p,q,r\}=\{2,3, 6\} \) sau \( p=q=r=3 \) sau \( (p,q,r)=(2,4,4) \) si permutari circulare.

Primul si ultimul caz nu convin, asadar p=q=r=3 care verifica identitatea(Hermite) pentru orice n natural.
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