SJ Edusphere on Instagram: "📘 Complete Trigonometry Formula Revision | Class XI & XII A full-length YouTube video is now live covering all major Trigonometry formulas needed for Class 11 & 12. In this video, we build concepts step by step: • Trigonometric table and quadrant rule • sin(A ± B), cos(A ± B), tan(A ± B) with logic • Trigonometry as sum & difference and product • Double angle, half angle and compound angle formulas • How these formulas form the base for calculus and board-level numer