CBSE Class 12 Mathematics 2026 Main Paper 65/1/3 · Q91 Marksdeterminants
CBSE Class 12 Mathematics 2026 Main Paper 65/1/3 · Question 9 (Determinants)
One of the values of x for which | cos x sin x; −cos x sin x | = 1 is
✅ Step-by-Step Solution
Final Answer: (B) π/4
- Determinant = cos x·sin x − sin x·(−cos x) = 2 sin x cos x = sin 2x.
- Set sin 2x = 1 ⇒ 2x = π/2 ⇒ x = π/4.
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