NTA Abhyas JEE Main2020MathematicsDeterminantsPractice
The value of ∆ = 1 sin 3 θ sin 3 θ 2 cos θ sin 6 θ sin 3 2 θ 4 cos 2 θ - 1 sin 9 θ sin 3 3 θ is equal to
Options
- A- 2
- B- 1
- C1
- D0
Correct answer
D. 0
Step-by-step solution
Multiplying C 1 by 3   s i n θ and dividing ∆ by 3   s i n θ , we get, ∆   = 1 3 sin ⁡ θ   3 sin ⁡ θ sin ⁡ 3 θ sin 3 ⁡ θ 3 sin ⁡ 2 θ sin ⁡ 6 θ sin 3 ⁡ 2 θ 3 sin ⁡ 3 θ sin ⁡ 9 θ sin 3 ⁡ 3 θ ∵ 3 sin ⁡ θ   4 cos 2 ⁡ θ - 1 = 3 sin ⁡ θ 3 - 4 sin 2 ⁡ θ = 3   sin ⁡ θ - 4 sin 3 ⁡ θ = 3 sin