Complete the identity.
-$\cos ( \alpha + \beta ) + \cos ( \alpha - \beta ) =$ ?
A) $2 \cos \alpha \cos \beta$
B) $\cos \alpha \cos \beta$
C) $2 \sin \alpha \cos \beta$
D) $\sin \beta \cos \alpha$

Question

Quizplus · Accepted Answer

The identity $\cos(\alpha + \beta) + \cos(\alpha - \beta) = 2 \cos \alpha \cos \beta$ is a standard trigonometric identity derived from the sum and difference formulas for cosine.

Complete the Identity cos⁡(α+β)+cos⁡(α−β)=\cos ( \alpha + \beta ) + \cos ( \alpha - \beta ) =cos(α+β)+cos(α−β)=

Complete the Identity $\cos ( \alpha + \beta ) + \cos ( \alpha - \beta ) =$