MHT CET202525 Apr 2025Morning ShiftMathematicsInverse Trigonometric FunctionsActual
The principal value of ⁻¹ [ 1 2 ( 9 10 - 9 10 ) ] is
Options
- A3 20
- B17 20
- C7 10
- D10
Correct answer
B. 17 20
Step-by-step solution
Let y = ⁻¹ [ 1 2 ( 9 10 - 9 10 ) ] . Since 1 2 = 4 = 4 , we can rewrite the expression as: y = ⁻¹ [ 4 9 10 - 4 9 10 ] Applying the identity A B - A B = (A+B) with A = 4 and B = 9 10 : y = ⁻¹ [ ( 4 + 9 10 ) ] Combining terms: 4 + 9 10 = 5 + 18 20 = 23 20 Thus, y = ⁻¹ ( 23 20 ) The principal value branch of ⁻¹ is [0, ] , but 23 20 > . Using (2 - ) = : 23 20 = (2 - 23 20 ) = 17 20 Since 0 17 20 , the principal value is: y = 17 20 Final answer: 17 20