NTA Abhyas JEE Main2020MathematicsIndefinite IntegrationPractice
The indefinite integral I = ∫ sin 2 x - cos 2 x 2019 sin x 2021 cos x 2021 d x simplifies to (where c is an integration constant)
Options
- Asin 2 x - cos 2 x 2020 2020 + c
- Btan x - cot x 2020 2020 + c
- Csin x - cos x 2020 2020 + c
- Dtan 2 x + cot 2 x 2020 2020 + c
Correct answer
B. tan x - cot x 2020 2020 + c
Step-by-step solution
I = ∫ sin 2 ⁡ x - cos 2 ⁡ x sin ⁡ x cos ⁡ x 2019 1 sin 2 ⁡ x cos 2 ⁡ x d x = ∫ tan ⁡ x - cot ⁡ x 2019 sin 2 ⁡ x + cos 2 ⁡ x sin 2 ⁡ x cos 2 ⁡ x d x = ∫ tan ⁡ x - cot ⁡ x 2019 sec 2 ⁡ x + c o s e c 2 x d x Let tan ⁡ x - cot ⁡ x = t ⇒ sec 2 ⁡ x + cosec 2 x d x = d t ∴ I = ∫ t 2019 d t = t 2020 2020 + c = tan ⁡ x - cot ⁡ x 2020 2020 + c