NTA Abhyas JEE Main2020MathematicsIndefinite IntegrationPractice
∫ sin 4 x cos 8 x d x is equal to (where C is an arbitrary constant)
Options
- A1 + tan 5 x 5 + tan 5 x 7 + C
- Btan 5 x 5 + tan 7 x 7 + C
- Ctan 7 x 5 + tan 5 x 7 + C
- DNone of these
Correct answer
B. tan 5 x 5 + tan 7 x 7 + C
Step-by-step solution
∫ sin 4 x cos 4 x cos 8 x cos 4 x . d x = ∫ tan 4 x . sec 4 x d x = ∫ tan 4 x 1 + tan 2 x sec 2 x d x = ∫ tan 4 x 1 + tan 2 x d tan x = ∫ t 4 1 + t 2 dt= t 5 5 + t 7 7 + C