What is the Formula of Cos C – Cos D ?

Solution :

The formula of cos C – cos D is 2 sin(\(C + D\over 2\)) sin(\(D – C\over 2\)).

Example : Express cos \(6\theta\) – cos \(8\theta\) as a product.

Solution : We have,

cos \(6\theta\) – cos \(8\theta\) = 2 sin(\(6\theta + 8\theta\over 2\)) sin(\(8\theta – 6 \theta\over 2\))

= 2 sin \(7\theta\) sin \(\theta\)


Similar Formulas

What is the Formula of Sin C + Sin D ?

What is the Formula of Cos C + Cos D ?

What is the Formula of Sin C – Sin D ?

Leave a Comment

Your email address will not be published.