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 $

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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. $