JEE Main202125 Feb 2021Evening ShiftMathematicsDefinite IntegrationActual
lim n → ∞ 1 n + n n + 1 2 + n n + 2 2 + … + n 2 n - 1 2 is equal to
Options
- A1 2
- B1 4
- C1 3
- D1
Correct answer
A. 1 2
Step-by-step solution
lim n → ∞ 1 n + n n + 1 2 + n n + 2 2 + … + n 2 n - 1 2 = lim n → ∞ ∑ r = 0 n - 1 n n + r 2 = lim n → ∞ ∑ r = 0 n - 1 n n 2 + 2 n r + r 2 = lim n → ∞ 1 n ∑ r = 0 n - 1 1 r / n 2 + 2 r / n + 1 = ∫ 0 1 d x x + 1 2 = - 1 x + 1 0 1 = 1 2