NTA Abhyas JEE Main2020MathematicsDefinite IntegrationPractice
The value of ∫ 0 π 2 cos 2 x cos 2 2 x cos 2 3 x cos 2 4 x d x is equal to
Options
- A0
- B1 2
- Cπ 2
- Dπ 4
Correct answer
A. 0
Step-by-step solution
Let the value of integral is I , then, Ι = ∫ 0 π 2 cos 2 x cos 2 2 x cos 2 3 x cos 2 4 x d x Ι = ∫ 0 π 2 - cos 2 x cos 2 2 x cos 2 3 x cos 2 4 x d x (applying f ( x ) = f ( a + b - x ) ) Adding, we get, 2 Ι = 0 ⇒ Ι = 0