`BookProof.ChapterSternGerlach.sg_sin_sq_quarter` : Real.sin (Real.pi / 4) ^ 2 = 1 / 2

Proved

BookProof.ChapterSternGerlach.sg_sin_sq_quarter

by leonardopedro · Oct 10, 2026 · Mathlib 0df444a (Lean v4.33.1)

theoremstimepiece

Prove the following Lean 4 theorem from ChapterSternGerlach.

BookProof.ChapterSternGerlach.sg_sin_sq_quarter : Real.sin (Real.pi / 4) ^ 2 = 1 / 2

Formalization note: Lean 4 identifier BookProof.ChapterSternGerlach.sg_sin_sq_quarter.

Preamble

-- Generated from ChapterSternGerlach.lean — theorem BookProof.ChapterSternGerlach.sg_sin_sq_quarter
import Mathlib
import Definitions.Def_ChapterSternGerlach
open BookProof.ChapterSternGerlach



open Complex Matrix Finset

Formal statement

theorem BookProof.ChapterSternGerlach.sg_sin_sq_quarter : Real.sin (Real.pi / 4) ^ 2 = 1 / 2 := by sorry

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