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Question #75847
The Question
Let , , and , , . Let and . A matrix is defined by its entries . If form an arithmetic progression with a non-zero common difference, and also form an arithmetic progression, find .
Options
- A.
0
- B.
1
- C.
x+y+z
- D.
xyz
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Monster
Ultra-high difficulty questions designed to test your limit, stamina, and deep conceptual understanding.
Concepts Behind This Question
Lagrange Identity|Linear Dependency of Rows|Integral Part and Fractional Part
Why This Question Is Tricky
Examiner Levers
Variable Manipulation
Algebraic solutions only (No numbers); tests pure symbolic logic.
Difficulty Boost : +4Common Mistakes
The problem disguises a determinant of cross products using the expanded form of the Lagrange Identity.
The core trap lies in evaluating the sum of the cyclic components U+V+W, which forms a determinant involving fractional and integer parts.
Students often fail to recombine {t} + [t] = t within the determinant to expose the linear dependency caused by the Arithmetic Progression condition, missing that the matrix becomes singular.
Quick Facts About This Question
Question Information
| Subject | Mathematics |
| Chapter | Vector Algebra - Class 12 |
| Concept | Lagrange Identity |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |