NTA Abhyas JEE Main2020MathematicsInverse Trigonometric FunctionsPractice
If sin - 1 1 3 + sin - 1 2 3 = sin - 1 x , then the value of x is
Options
- A0
- B( 5 - 4 2 ) 9
- C( 5 + 4 2 ) 9
- Dπ 2
Correct answer
C. ( 5 + 4 2 ) 9
Step-by-step solution
Given that, sin - 1 1 3 + sin - 1 2 3 = sin 1 x Taking sine on both sides ⇒ 1 3 1 - 4 9 + 2 3 1 - 1 9 = x ⇒ 1 3 . 5 3 + 2 3 . 8 3 = x ⇒ 5 + 4 2 9 = x ∴ x = 5 + 4 2 9