NTA Abhyas JEE Main2020MathematicsInverse Trigonometric FunctionsPractice
If sin - 1 ⁡ 2 a 1 + a 2 + sin - 1 ⁡ 2 b 1 + b 2 = 2 cot - 1 ⁡ 1 x , then x is equal to ∀ a , b ∈ 0 , 1
Options
- Aa - b 1 + a b
- Bb 1 + a b
- Cb 1 - a b
- Da + b 1 - a b
Correct answer
D. a + b 1 - a b
Step-by-step solution
Since, sin - 1 2 x 1 + x 2 = 2 tan - 1 x for x ∈ - 1 , 1 s i n - 1 2 a 1 + a 2 + s i n - 1 2 b 1 + b 2 = 2 cot - 1 1 x ⇒ tan - 1 a + tan - 1 b = tan - 1 x ⇒ tan - 1 a + b 1 - a b = tan - 1 x ⇒ x = a + b 1 - a b