Trigonometric Identities Question 159
Question: $ \cot x-\tan x= $
[MP PET 1986]
Options:
A) $ \cot ,2x $
B) $ 2{{\cot }^{2}}x $
C) $ 2\cot ,2x $
D) $ {{\cot }^{2}},2x $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \cot x-\tan x=\frac{\cos x}{\sin x}-\frac{\sin x}{\cos x}=\frac{{{\cos }^{2}}x-{{\sin }^{2}}x}{\sin x,\cos x} $ $ =\frac{2,\cos ,2x}{\sin ,2x}=2\cot 2x. $