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Precalculus

Lesson 9: Angle addition identities

Using the trig angle addition identities

CCSS.Math: HSF.TF.C.9

Find cosine, left parenthesis, angle, B, A, C, minus, 60, degrees, right parenthesis.

(Choice A)
start fraction, 6, divided by, 13, end fraction, minus, start fraction, 5, divided by, 26, end fraction, square root of, 3, end square root
(Choice B)
start fraction, 5, divided by, 26, end fraction, minus, start fraction, 6, divided by, 13, end fraction, square root of, 3, end square root
(Choice C)
start fraction, 6, divided by, 13, end fraction, plus, start fraction, 5, divided by, 26, end fraction, square root of, 3, end square root
(Choice D)
start fraction, 5, divided by, 26, end fraction, plus, start fraction, 6, divided by, 13, end fraction, square root of, 3, end square root

Stuck?