AP EAMCET202119 Aug 2021Evening ShiftMathematicsDefinite IntegrationActual
If ∫ 0 π / 2 tan n x d x = k ∫ 0 π / 2 cot n x d x , then
Options
- Ak = 1
- Bk = 2
- Ck = 1 2
- Dk = 3
Correct answer
A. k = 1
Step-by-step solution
As, I = ∫ 0 π / 2 tan n x d x Apply the properties of definite integration: replace x → π 2 - t   ⇒   d x d t = - 1 , and upper limit x = π 2   ⇒   π 2 - t = π 2   ⇒   t = 0 Similarly, lower limit x = 0   ⇒   π 2 - t = 0   ⇒   t = π 2 I = ∫ 0 π / 2 tan n x d x = ∫ π 2 0 tan n π 2 - t - d t = - ∫ 0 π 2 tan n π 2 - t - d t = ∫ 0 π 2 tan n