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Trigonometry

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Moderate

Angle Addition/Subtraction Formula for Cosine (Radians)

TRIG-BEF5DE

Find the exact $\cos{\cfrac{19\pi}{12}}$ by using the angle addition or subtraction formula for cosine.

A

$$1$$

B

$$\cfrac{\sqrt2-\sqrt6}{4}$$

C

$$\cfrac{-\sqrt6-\sqrt2}{4}$$

D

$$\cfrac{\sqrt6+\sqrt2}{4}$$

E

$$\cfrac{\sqrt6-\sqrt2}{4}$$