Lec_001_II, Real Analysis, If m is natural & not perfect square then square root m is not rational.

Whole-channel inclusion: MathLogic is an honest teaching channel (title sample + 3 transcripts read: The one sample with a transcript is a structured math lecture deriving moment of inertia formulas, consistent with the channel's teaching verdict.); this title passed a strict title check (sonnet) after a labelling pass.