Derivation: Double Angle Formulae via Matrices

[@세종대왕-x8p]

ur finally back!! Can you do more ENGAA questions please? I find your videos rlly helpful. Concise, logical, with clear explanations :D

[@dewr98]

Thank you! I sure can, what ENGAA questions would you like help with?

[@dewr98]

Also feel free to check out @OxbridgeFormula for some ENGAA/NSAA solutions, they recently uploaded some (I used to make some of those as well)

[@세종대왕-x8p]

I think 2023 S1 questions would be helpful :)