Find all triples of real numbers that satisfy the system of equations
Razvan Gelca.
USA Team Selection Test
Solution
We are given the system of equations:
To find all triples of real numbers that satisfy these equations, we analyze the behavior of the functions involved.
1. **Case :**
- For , the function is increasing. Thus, from the first equation, .
- From the third equation, since , we have , implying .
- However, substituting into the second equation gives , implying , which contradicts .
2. **Case :**
- For , from the third equation, , implying .
- From the second equation, .
- Substituting into the first equation gives , implying , which contradicts .
3. **Verification of :**
- Substituting , , and into the equations:
- These values satisfy all three equations.
Thus, the only solution is:
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