Question 148
The real numbers $x, y, z$ satisfy $x+y+z=a$, where $a$ is a fixed real number. Determine the maximum possible value of the sum $S=xy+yz+zx$. For which values of $x, y, z$ is this maximum value attained?
MathNet 2023-part-03 — 191 problems (EN–VI) Question 148
Math Olympiad Vault · MathNet 2023-part-03 — 191 problems (EN–VI)