Problem:
Let be nonzero real numbers. Suppose that for each , where . Compute the maximum possible number of integers such that .
Proposed by: Akash Das
Problem:
Let be nonzero real numbers. Suppose that for each , where . Compute the maximum possible number of integers such that .
Proposed by: Akash Das
Solution:
Let the answer be . If , there would exist two consecutive positive terms which contradicts the assumption that . Thus, . If , then the s must alternate between positive and negative. WLOG, assume and for each . Then, we have
Multiplying the first equation over all gives us , while multiplying the second equation over all gives us . Thus, we must have .
is possible by the following construction: