Two powerful u-substitutions for integrals

Feynman Academy course: https://feynman-academy-course.vercel.app/#/join Chapters 1 and 2 are free. Chapter 3 and beyond start with a 7-day trial, then $10/month unless canceled. Subscribe: https://www.youtube.com/channel/UCepKxh_j0SH2cw0nbY9FwZQ?sub_confirmation=1 Course path (Jan 18, 2026 and newer) Lesson 19 of 32 Start here: https://youtu.be/8xq0RW1VurI Previous lesson: https://youtu.be/rMXMzJ4yzsA Next lesson: https://youtu.be/b0v6vesiOWU About this lesson: We crush a difficult trigonometric integral using the Universal Substitution (Weierstrass) method. Then, we use King's Property to reveal a hidden symmetry between Sine and Cosine.