Question

Use the sum and difference identities to rewrite the following expression as a trigonometric function of a single number.2лम2л五COS(15) w() - Sin(ਤੋਂ ) sin()-(COS

Answer 1

The sum identity for Cosine is given as:

$\cos (A+B)=\cos A\cos B-\sin A\sin B$

This is the same for the given equation in the equation, assuming:

$\begin{gathered} A=\frac{2\pi}{5} \\ B=\frac{\pi}{12} \end{gathered}$

Hence, the correct answer is:

$\cos (A+B)=\cos A\cos B-\sin A\sin B$