99 Percentile Qs Bank for JEE MainMathematicsDefinite Integration
The value of the integral ∫ 0 1 1 − x 1 + x d x is
Options
- A- 1
- B1
- Cπ 2 − 1
- Dπ 2 + 1
Correct answer
C. π 2 − 1
Step-by-step solution
I = ∫ 0 1 [ 1 − x 1 + x × 1 − x 1 − x ] d x ( rationalising the denominator ) = ∫ 0 1 1 − x 1 − x 2 d x = ∫ 0 1 1 1 − x 2 d x − ∫ 0 1 x d x 1 − x 2 ⇒ I = [ sin − 1 x ] 0 1 − 1 2 ∫ 0 1 2 x 1 − x 2 d x = [ π 2 − 0 ] + 1 2 [ 2 1 − x 2 ] 0 1 = π 2 + [ 0 − 1 ] = π 2 − 1