lean_workbook_plus_11950
OpenProve:
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_11950 x : Real.cos (3 * x) = Real.cos x * (1 - 4 * (Real.sin x)^2) := by sorry
Source
Prove:
import Mathlib.Analysis.Complex.Basic
theorem lean_workbook_plus_11950 x : Real.cos (3 * x) = Real.cos x * (1 - 4 * (Real.sin x)^2) := by sorry