JEE Main20203 Sep 2020Evening ShiftMathematicsDefinite IntegrationActual
If the value of the integral ∫ 0 1 2 x 2 1 - x 2 3 2 d x is k 6 , then k is equal to:
Options
- A2 3 + π
- B2 3 - π
- C3 2 + π
- D3 2 - π
Correct answer
B. 2 3 - π
Step-by-step solution
k 6 = ∫ 0 1 2 x 2 1 - x 2 3 2 d x Let x = sin θ ⇒ d x = cos θ d θ ⇒ k 6 = ∫ 0 π 6 sin 2   θ 1 - sin 2   θ 3 2 cos θ d θ ⇒ k 6 = ∫ 0 π 6 sin 2   θ cos 3   θ cos θ d θ ⇒ k 6 = ∫ 0 π 6 tan 2 θ d θ = ∫ 0 π 6 s e c 2 θ - 1 d θ ⇒ k 6 = tan θ - θ 0 π 6 = 1 3 - π 6 = 2 3 - π 6 ⇒ k = 2 3 - π