Mathematics · essential
Angle sum and difference formulas for JEE
Trigonometrical identities and trigonometrical functions
Formula
\[\sin(A\pm B)=\sin A\cos B\pm \cos A\sin B,\\ \cos(A\pm B)=\cos A\cos B\mp \sin A\sin B,\\ \tan(A\pm B)=\dfrac{\tan A\pm \tan B}{1\mp \tan A\tan B}\]
Variables: \(A,B\) are angles.
Conditions: For tangent, denominator nonzero.
Expansion, reduction, solving equations, proving identities.