MHT CET2018MathematicsInverse Trigonometric Functions
If tan - 1 2 x + tan - 1 3 x = π 4 , then x =
Options
- A- 1
- B1 3
- C1 6
- D1 2
Correct answer
C. 1 6
Step-by-step solution
tan − 1 2 x + tan − 1 3 x = π 4 tan − 1 ( 2 x + 3 x 1 − 6 x 2 ) = π 4 ; x > 0 5 x 1 − 6 x 2 = 1 5 x = 1 − 6 x 2 6 x 2 + 5 x − 1 = 0 6 x 2 + 6 x − x − 1 = 0 6 x ( x + 1 ) − 1 ( x + 1 ) = 0 ( 6 x − 1 ) ( x + 1 ) = 0 x ≠ − 1 ; x = 1 6