Prove2Me

lean_workbook_plus_12099

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

Prove that sin⁡50∘=cos⁡40∘\sin 50^{\circ} = \cos 40^{\circ}

Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_12099 (x : ℝ) : sin (50 * π / 180) = cos (40 * π / 180)   :=  by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook

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