JEE Main202227 Jun 2022Evening ShiftMathematicsInverse Trigonometric FunctionsActual
The value of cot ∑ n = 1 50 tan - 1 1 1 + n + n 2 is
Options
- A25 26
- B50 51
- C26 25
- D52 51
Correct answer
C. 26 25
Step-by-step solution
Now ∑ n = 1 50 tan - 1 1 1 + n + n 2 = ∑ n = 1 50 tan - 1 n + 1 - n 1 + n n + 1 = ∑ n = 1 50 tan - 1 n + 1 - tan - 1 n = tan - 1 51 - tan - 1 1 = tan - 1 51 - 1 1 + 51 = tan - 1 50 52 = cot - 1 26 25 So cot ∑ n = 1 50 tan - 1 1 1 + n + n 2 = cot cot - 1 26 25 = 26 25