Precalculus (10th Edition)

Published by Pearson
ISBN 10: 0-32197-907-9
ISBN 13: 978-0-32197-907-0

Chapter 7 - Analytic Trigonometry - 7.5 Sum and Difference Formulas - 7.5 Assess Your Understanding - Page 487: 5


$-$ (minus sign)

Work Step by Step

The formula for the cosine of the sum of two angles $A$ and $B$ is: $\cos(A+B)=\cos A \cos B-\sin A \sin B$ Hence, the answer is "$\color{blue}{-}$" (minus sign)
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