JEE Main20199 Jan 2019Morning ShiftMathematicsDefinite IntegrationActual
The value of ∫ 0 π cos x 3 d x is
Options
- A2 3
- B0
- C4 3
- D- 4 3
Correct answer
C. 4 3
Step-by-step solution
I = ∫ 0 π cos x 3 d x = 2 ∫ 0 π 2 c o s 3 x d x = 2 ∫ 0 π 2 1 - s i n 2 x c o s x d x = 2 ∫ 0 π 2 c o s x d x - ∫ 0 π 2 s i n 2 x c o s x d x = 2 s i n x - s i n 3 x 3 0 π 2 = 2 1 - 1 3 - 0 + 0 = 4 3