NTA Abhyas JEE Main2020MathematicsInverse Trigonometric FunctionsPractice
The value of s i n c o t - 1 c o s c o t - 1 1 x is equal to x > 0
Options
- A1 + x 2 2 + x 2
- B1 - x 2 2 + x 2
- C1 + x 2 2 - x 2
- D2 + x 2 1 + x 2
Correct answer
A. 1 + x 2 2 + x 2
Step-by-step solution
Let c o t - 1 1 x = α ⇒ tan α = x So, cos α = 1 1 + x 2 ∴ sin cot - 1 cos tan - 1 x = s i n c o t - 1 1 1 + x 2 Let c o t - 1 1 1 + x 2 = β ⇒ cot β = 1 1 + x 2 ∴ sin β = ( 1 + x 2 ) ( 2 + x 2 ) ∴ sin β = sin c o t - 1 cos cot - 1 1 x = 1 + x 2 2 + x 2