1.

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°

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°



Discussion

No Comment Found

Related InterviewSolutions