Trigonometric Identities Question 303
Question: $ \sqrt{2+\sqrt{2+2\cos 4\theta }}= $
Options:
A) $ \cos \theta $
B) $ \sin \theta $
C) $ 2\cos \theta $
D) $ 2\sin \theta $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \sqrt{2+\sqrt{2+2\cos 4\theta }} $ = $ \sqrt{2+\sqrt{2.2{{\cos }^{2}}2\theta }} $ $ =\sqrt{2+2\cos 2\theta }=\sqrt{4{{\cos }^{2}}\theta }=2\cos \theta $ .
BETA
