lean_workbook_plus_14746

Proved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

$P(2,2): f(2)^2 = 2f(2)$ . So $f(2) = 0$ or $f(2) = 2$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_14746  (f : ℝ → ℝ)
  (h₀ : (∀ x, (f x)^2 = 2 * f x)) :
  f 2 = 0 ∨ f 2 = 2   :=  by sorry

Source