Question

Use an addition or subtraction formula to write the expression as a trigonometric function of one number:\\ $\cos \frac{3\pi}{7} \cos \frac{2\pi}{21} + \sin \frac{3\pi}{7} \sin \frac{2\pi}{21} = \cos \frac{\pi}{A} = \frac{B}{2}$.\\A = \\ B =

          Use an addition or subtraction formula to write the expression as a trigonometric function of one number:\\
$\cos \frac{3\pi}{7} \cos \frac{2\pi}{21} + \sin \frac{3\pi}{7} \sin \frac{2\pi}{21} = \cos \frac{\pi}{A} = \frac{B}{2}$.\\A = \\
B =

Use an addition or subtraction formula to write the expression as a trigonometric function of one number:

cos(3π)/(7)cos(2π)/(21) + sin(3π)/(7)sin(2π)/(21) = cos(π)/(A) = (B)/(2).
A =

B =

Added by Mariano A.

Precalculus with Limits

Ron Larson 2nd Edition

Instant Answer

Solved by Expert Ankit Singh

05/06/2022

Step 1

Step 1: Apply the cosine addition formula: cos(A)cos(B) + sin(A)sin(B) = cos(A - B) Show more…

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Use an addition or subtraction formula to write the expression as a trigonometric function of one number: cos((3pi )/(7))cos((2pi )/(21))+sin((3pi )/(7))sin((2pi )/(21))=cos((pi )/(A))=(B)/(2) Use an addition or subtraction formula to write the expression as a trigonometric function of one number: A=