MathematicsProperties of Inverse Trigonometric FunctionsJEE Advanced 1981Easy
Visualized Solution (Hindi)
Analyze the Expression
- Given expression: cos(2cos−1x+sin−1x)
- At x=51
- Step 1: Split the term 2cos−1x
- cos(cos−1x+cos−1x+sin−1x)
Apply Inverse Identity
- Recall the identity: cos−1x+sin−1x=2π
- Substitute this into the expression:
- cos(cos−1x+2π)
Trigonometric Reduction
- Use the allied angle formula: cos(2π+θ)=−sinθ
- Here, θ=cos−1x
- Expression becomes: −sin(cos−1x)
Visualizing the Triangle
- Let θ=cos−1x⟹cosθ=x
- In a right triangle: Base=x, Hypotenuse=1
- Perpendicular=1−x2
- Therefore, sin(cos−1x)=1−x2
- Expression: −1−x2
Final Substitution and Result
- Substitute x=51:
- −1−(51)2
=−1−251 - −2524
=−524 - Final Answer: −526
00:00 / 00:00
Conceptually Similar Problems
MathematicsProperties of Inverse Trigonometric FunctionsJEE Advanced 1983Easy
MathematicsProperties of Inverse Trigonometric FunctionsJEE Advanced 2002Easy
MathematicsProperties of Inverse Trigonometric FunctionsJEE Advanced 2001Moderate
MathematicsFundamental Theorem & Properties of Definite IntegralsJEE Advanced 1997Moderate
MathematicsIntegration by SubstitutionJEE Advanced 1985Moderate
MathematicsSolving Inverse Trigonometric EquationsJEE Main 2007Easy
MathematicsFundamental Theorem & Properties of Definite IntegralsJEE Advanced 2001Moderate
MathematicsTrigonometric Ratios and IdentitiesJEE Advanced 1991Moderate
MathematicsFundamental Theorem & Properties of Definite IntegralsJEE Advanced 1986Moderate
MathematicsFundamental Theorem & Properties of Definite IntegralsJEE Main 2005Easy