Maths Guide 11th Std Tamil Nadu State Board May 2026

(\sin 3A = 3\sin A - 4\sin^3 A), (\cos 3A = 4\cos^3 A - 3\cos A).

(\frac3\sin A - 4\sin^3 A\sin A - \frac4\cos^3 A - 3\cos A\cos A).

(3 - 4\sin^2 A - [4\cos^2 A - 3]) = (3 - 4\sin^2 A - 4\cos^2 A + 3).