NTA Abhyas JEE Main2020MathematicsDefinite IntegrationPractice
Let Ι 1 = ∫ 0 1 ln x x 2 + 4 x + 1 d x and Ι 2 = ∫ 1 ∞ ln x x 2 + 4 x + 1 d x , then
Options
- AΙ 1 = Ι 2
- BΙ 1 > Ι 2
- CΙ 1 + Ι 2 = 0
- DΙ 1 = 2 Ι 2
Correct answer
A. Ι 1 = Ι 2
Step-by-step solution
In Ι 2 substitute x = 1 t ⇒ d x = - d t t 2 So, Ι 2 = - ∫ 1 0 ln ⁡ t t 2 + 4 t + 1 ⋅ t 2 - d t t 2 = ∫ 0 1 - ln ⁡ t t 2 + 4 t + 1 d t = Ι 1 a s   ln ⁡ t = - ln ⁡ t   i n   0,1