JEE 2023 — Mathematics PYQ
JEE | Mathematics | 2023If \sin^{-1} \frac{\alpha}{17} + \cos^{-1} \frac{4}{5} - \tan^{-1} \frac{77}{36} = 0, 0 < \alpha < 13, then sin−1(sinα)+cos−1(cosα) is equal to:
Choose the correct answer:
- A.
16
- B.
0
- C.
π
(Correct Answer) - D.
16−5π
π
Explanation
Solution:
Sabse pehle α nikaalte hain. Maana cos−154=tan−143.
Yadi tanθ=8/15, toh sinθ=8/17. Isliye α=8.
Ab humein nikalna hai: sin−1(sin8)+cos−1(cos8).
Kyunki 8 radians lagbhag 2.5π ke barabar hai (8≈2.5×3.14):
-
sin−1(sin8)=3π−8 (Kyunki 2.5\pi < 8 < 3\pi range mein sin−1sinx=(2n+1)π−x hota hai)
-
cos−1(cos8)=8−2π (Kyunki 2\pi < 8 < 3\pi range mein cos−1cosx=x−2π hota hai)
Sum: (3π−8)+(8−2π)=π
Correct Option: (3) π
Explanation
Solution:
Sabse pehle α nikaalte hain. Maana cos−154=tan−143.
Yadi tanθ=8/15, toh sinθ=8/17. Isliye α=8.
Ab humein nikalna hai: sin−1(sin8)+cos−1(cos8).
Kyunki 8 radians lagbhag 2.5π ke barabar hai (8≈2.5×3.14):
-
sin−1(sin8)=3π−8 (Kyunki 2.5\pi < 8 < 3\pi range mein sin−1sinx=(2n+1)π−x hota hai)
-
cos−1(cos8)=8−2π (Kyunki 2\pi < 8 < 3\pi range mein cos−1cosx=x−2π hota hai)
Sum: (3π−8)+(8−2π)=π
Correct Option: (3) π

