NTA Abhyas JEE Main2020MathematicsInverse Trigonometric FunctionsPractice
The value of x for which sin cot - 1 1 + x = cos ( tan - 1 x ) is
Options
- A1 2
- B1
- C0
- D- 1 2
Correct answer
D. - 1 2
Step-by-step solution
Let, cot - 1 ⁡ x + 1 = θ and tan - 1 ⁡ x = ϕ Now, given equation becomes sin θ = cos ϕ ⇒ 1 1 + x + 1 2 = 1 1 + x 2 ⇒ x + 1 2 + 1 = x 2 + 1 ⇒ x = - 1 2