Difficulty: Easy
Correct Answer: 2
Explanation:
Introduction / Context:
This is a trig identity/evaluation problem. Using the given r-scaled sine and cosine helps find tan θ directly by division, and the Pythagorean identity can verify consistency of r and θ.
Given Data / Assumptions:
Concept / Approach:
Compute tan θ = (r sin θ)/(r cos θ) = 1/√3. Then plug into S. Optionally, confirm r by squaring and summing to ensure a consistent setup.
Step-by-Step Solution:
Verification / Alternative check:
If tan θ = 1/√3, then θ corresponds to 30° in the principal acute range; the expression evaluates to 2 as found.
Why Other Options Are Wrong:
Values like √3 or 1 occur if tan θ is misread as √3 or 0.
Common Pitfalls:
Dividing in the wrong order (cos/sin) or forgetting that √3 * (1/√3) simplifies to 1.
Final Answer:
2
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