lean_workbook_plus_17784

Open

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

Determine if the function $y=\dfrac{\sin x}{1+x^4}$ is odd or even without graphing.

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_17784 (f : ℝ → ℝ) (f_def : ∀ x, f x = sin x / (1 + x ^ 4)) : ∀ x, f (-x) = -f x   :=  by sorry

Source