Question 78Asked in BPSC TRE 2.0 (2023) Mathematics Class 9-10 (Re-exam)

Let A = [[0, 1], [−1, 1]]. Then the smallest positive integer n such that Aⁿ = I isमानें कि A = [[0, 1], [−1, 1]] है। तो न्यूनतम धन पूर्णांक n ताकि Aⁿ = I है

मानें कि A = [[0, 1], [−1, 1]] है। तो न्यूनतम धन पूर्णांक n ताकि Aⁿ = I है
  1. A11
  2. B22
  3. C66
  4. DMore than one of the aboveउपर्युक्त में से एक से अधिक
  5. ENone of the aboveउपर्युक्त में से कोई नहीं
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Correct answer: (C) 66

Explanation

The characteristic polynomial is λ² − λ + 1, so A² = A − I and A³ = −I. Hence A⁶ = I, and no smaller power equals I.अभिलाक्षणिक बहुपद λ² − λ + 1 है, अतः A² = A − I और A³ = −I। इसलिए A⁶ = I है और कोई छोटी घात I के बराबर नहीं है।

From BPSC TRE 2.0 (2023) Mathematics Class 9-10 (Re-exam) — Previous Year Paper

This is question 78 of BPSC TRE 2.0 (2023) Mathematics Class 9-10 (Re-exam) — Previous Year Paper. See all questions of this paper with answers, or attempt the paper as a timed online test to get your score and all-India rank.