If x=sin−1(sin10) and y=cos−1(cos10), then y−x is equal to:
(A)π✓ Correct
(B)7π
(C)0
(D)10
Answer: (A)
Solution
Both arguments are in radians, and 10 lies between 3π≈9.42 and 4π≈12.57. For sin−1(sin10) to land in [−2π,2π], use x=3π−10. For cos−1(cos10) to land in [0,π], use y=4π−10. Then y−x=(4π−10)−(3π−10)=π.
JEE Main · 2019 · 09 Jan 2019 · Shift 2 · Single correct option