MHT CET20192 May 2019Morning ShiftMathematicsInverse Trigonometric FunctionsActual
The value of tan - 1 1 3 + tan - 1 1 5 + tan - 1 1 7 + tan - 1 1 8 is ________
Options
- A11 π 5
- Bπ 4
- Cπ
- D3 π 4
Correct answer
B. π 4
Step-by-step solution
Let L = t a n - 1 1 3 + t a n - 1 1 5 + t a n - 1 1 7 + t a n - 1 1 8 = t a n - 1 1 3 + 1 5 1 - 1 3 . 1 5 + t a n - 1 1 7 + 1 8 1 - 1 7 . 1 8 = t a n - 1 8 14 + t a n - 1 15 55 = t a n - 1 4 7 + t a n - 1 3 11 = t a n - 1 4 7 + 3 11 1 - 4 7 . 3 11 = t a n - 1 44 + 21 77 - 12 t a n - 1 65 65 = π 4