Lean-Workbook Plus 35485: Trigonometric inequality

Proved

WorkbookRestored.plus_35485

by wamlart · Sep 12, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

lean-workbookrestored-importssource-checked

If $y=2\sin p$ and $-\pi/2\le p\le\pi/2$ , then $-2\le y\le2$ . This gives the bounding component of the source’s range question.

Source: Lean-Workbook row lean_workbook_plus_35485 (Apache-2.0). The unchanged proposition comes from the original record; its missing mathematical imports and namespaces are restored here.

Preamble

import Mathlib.Analysis.SpecialFunctions.Trigonometric.Basic
open Real

Formal statement

theorem WorkbookRestored.plus_35485 (p y : ℝ) (h₁ : y = 2 * Real.sin p) (h₂ : -Real.pi / 2 ≤ p ∧ p ≤ Real.pi / 2) : -2 ≤ y ∧ y ≤ 2   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, row lean_workbook_plus_35485; immutable original Prove2Me node a50710b9-1837-47a4-b1dc-e5df4dfa51d8

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