NTA Abhyas JEE Main2020MathematicsDefinite IntegrationPractice
The value of the integral ∫ - 1 1 d x 1 + x 2 1 + e x is equal to
Options
- Aπ 4
- Bπ 2
- Cπ
- D0
Correct answer
A. π 4
Step-by-step solution
Let, I = ∫ - 1 1 d x 1 + x 2 1 + e x As, ∫ - a a f x d x = ∫ 0 a f x + f - x d x So, I = ∫ 0 1 1 1 + x 2 1 1 + e x + 1 1 + e - x d x ⇒ I = ∫ 0 1 1 1 + x 2 = tan - 1 x 0 1 = π 4