Question:medium

If \( x \neq 0 \), then \[ \frac{\sin(\pi + x)\cos\left(\frac{\pi}{2} + x\right)\tan\left(\frac{3\pi}{2} - x\right)\cot(2\pi - x)}{\sin(2\pi - x)\cos(2\pi + x)\csc(-x)\sin\left(\frac{3\pi}{2} + x\right)} = \]

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To simplify trigonometric expressions, apply standard identities such as \( \sin(\pi + x) = -\sin x \), and ensure careful cancellation of like terms.
Updated On: Mar 28, 2026
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The Correct Option is C

Solution and Explanation

The objective is to simplify the expression: \[ \frac{\sin(\pi + x) \cos\left(\frac{\pi}{2} + x\right) \tan\left(\frac{3\pi}{2} - x\right) \cot(2\pi - x)}{\sin(2\pi - x) \cos(2\pi + x) \csc(-x) \sin\left(\frac{3\pi}{2} + x\right)}. \]

Step 1: Simplify Individual Trigonometric Functions

Applying standard trigonometric identities yields:

\( \sin(\pi + x) = -\sin(x) \)

\( \cos\left(\frac{\pi}{2} + x\right) = -\sin(x) \)

\( \tan\left(\frac{3\pi}{2} - x\right) = \cot(x) \)

\( \cot(2\pi - x) = -\cot(x) \)

\( \sin(2\pi - x) = -\sin(x) \)

\( \cos(2\pi + x) = \cos(x) \)

\( \csc(-x) = -\csc(x) \)

\( \sin\left(\frac{3\pi}{2} + x\right) = -\cos(x) \)

Substitute these simplified terms back into the original expression.

Step 2: Substitute Simplified Terms into the Expression

The numerator simplifies to: \[ (-\sin x)(-\sin x)(\cot x)(-\cot x) = -\sin^2(x) \cot^2(x). \]

The denominator simplifies to: \[ (-\sin x)(\cos x)(-\csc x)(-\cos x) = -\sin(x) \cos^2(x) \csc(x). \]

Step 3: Combine and Simplify the Expression

The expression now is: \[ \frac{-\sin^2(x) \cot^2(x)}{-\sin(x) \cos^2(x) \csc(x)}. \]

Utilizing the identities \( \cot(x) = \frac{\cos(x)}{\sin(x)} \) and \( \csc(x) = \frac{1}{\sin(x)} \), we get: \[ \frac{\sin^2(x) \left(\frac{\cos^2(x)}{\sin^2(x)}\right)}{\sin(x) \cos^2(x) \left(\frac{1}{\sin(x)}\right)}. \]

Further simplification leads to: \[ \frac{\cos^2(x)}{\cos^2(x)} = 1. \]

Final Answer: The simplified value of the expression is: \[ \boxed{1 \, \text{(Option C)}}. \]

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