Guaranteed Real Roots
Algebra
Level
5
Find the largest positive integer \(n\) such that for all real numbers \(a_1\), \(a_2\), \(\dots , a_{n+1} \), the equation \( a_{n+1} x^2 - 2x \sqrt{ a_1^2 + a_2^2 + \cdots + a_{n+1}^2} + (a_1 + a_2 + \cdots + a_n) = 0\) has real roots.
Details and assumptions
Clarification: \( a_1, a_2, \ldots, a_{n+1}\) is any set of real numbers. There is no restrictions stated in the problem. They do not need to be integers, nor always positive, nor an arithmetic progression.
by
Calvin Lin