Trigonometric Identities Question 302
Question: $ \text{cosec }A-2\cot 2A\cos A= $
Options:
A) $ 2\sin A $
B) $ \sec A $
C) $ 2\cos A\cot A $
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
$ cosec,A-2\cot 2A\cos A=\frac{1}{\sin A}-\frac{2\cos A\cos 2A}{\sin 2A} $ $ =\frac{1}{\sin A}-\frac{2\cos A\cos 2A}{2\sin A\cos A}=\frac{1-\cos 2A}{\sin A}=\frac{2{{\sin }^{2}}A}{\sin A} $ $ =2\sin A $ .
BETA
