Mathematics · essential
Sum to product formulas for JEE
Trigonometrical identities and trigonometrical functions
Formula
\[\sin C+\sin D=2\sin\dfrac{C+D}{2}\cos\dfrac{C-D}{2},\\ \sin C-\sin D=2\cos\dfrac{C+D}{2}\sin\dfrac{C-D}{2},\\ \cos C+\cos D=2\cos\dfrac{C+D}{2}\cos\dfrac{C-D}{2},\\ \cos C-\cos D=-2\sin\dfrac{C+D}{2}\sin\dfrac{C-D}{2}\]
Variables: \(C,D\) are angles.
Transformation of sums/differences, identity proof, equation solving.