NTA Abhyas JEE Main2020MathematicsDefinite IntegrationPractice
If the integral I = ∫ 0 19 π d x 1 + e cos 3 x has the value k π 2 , then k 2 is equal to
Correct answer
9.5
Step-by-step solution
Applying a + b - x and adding, 2 I = ∫ 0 19 π 1 1 + e cos 3 x + 1 1 + e - cos 3 x d x ⇒ 2 I = ∫ 0 19 π 1 d x = x 0 19 π ⇒ I = 19 π 2 ∴ k = 19 Hence, k 2 = 19 2 = 9.5