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If cos (x - y) \(=\frac{\sqrt 3}{2}\) and sin (x + y) \(=\frac{1}{2}\), then the value of x (0 ≤ x ≤ 90) is:1. 45° 2. 30°3. 15°4. 60° |
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Answer» Correct Answer - Option 2 : 30° Given: cos (x - y) = √3/2 sin (x + y) = 1/2 Formula: cos30° = √3/2 sin30° = 1/2 Calculation: cos(x - y) = √3/2 ⇒ cos(x - y) = cos30° (x - y) = 30° ---- (1) sin(x + y) = 1/2 ⇒ sin(x + y) = sin30° (x + y) = 30 ---- (2) Add equation (1) and equation (2), we get 2x = 60° ∴ x = 30° |
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