JEE Main2013MathematicsIndefinite IntegrationActual
If ∫ f ( x ) d x = ψ ( x ) , then ∫ x 5 f ( x 3 ) d x , is equal to
Options
- A1 3 x 3 ψ ( x 3 ) − ∫ x 2 ψ ( x 3 ) d x + c
- B1 3 [ x 3 ψ ( x 3 ) − ∫ x 3 ψ ( x 3 ) d x ] + c
- C1 3 [ x 3 ψ ( x 3 ) − ∫ x 2 ψ ( x 3 ) d x ] + c
- D1 3 x 3 ψ ( x 3 ) − 3 ∫ x 3 ψ ( x 3 ) d x + c
Correct answer
A. 1 3 x 3 ψ ( x 3 ) − ∫ x 2 ψ ( x 3 ) d x + c
Step-by-step solution
∫ x 5 f x 3 d x = ∫ x 3 . x 2 f x 3 d x   Applying integration by parts, we get = x 3 ∫ x 2 f x 3 d x - ∫ d d x x 3 ∫ x 2 f x 3 d x = 1 3 x 3 ψ x 3 - ∫ x 2 ψ x 3 d x + c , where c is the constant of integration.