Prove that the axiom of the reals holds |x*y| < or = 1/2 * (x^2 + y^2)

Question

Aufgabe:

Prove that the axiom of the reals holds |x*y| ≤ 1/2 * (x^2 + y^2)

Comments

Wie lautet die Aufgabe?

Answer 1

Tipp: (|x| - |y|)² ≥ 0.