Question 76Asked in BPSC TRE 2.0 (2023) Mathematics Class 9-10 (Re-exam)

Let gₙ(x) = nx / (1 + n²x²), x ∈ [0, ∞) Which of the following is true as n → ∞?मान लीजिए gₙ(x) = nx / (1 + n²x²), x ∈ [0, ∞)

Let gₙ(x) = nx / (1 + n²x²), x ∈ [0, ∞) Which of the following is true as n → ∞?
मान लीजिए gₙ(x) = nx / (1 + n²x²), x ∈ [0, ∞) n → ∞ होने पर निम्न में से कौन-सा सत्य है?
  1. Agₙ → 0 pointwise but not uniformlygₙ → 0 बिंदुवार लेकिन एकसमानतः नहीं
  2. Bgₙ → 0 uniformlygₙ → 0 एकसमानतः
  3. Cgₙ(x) → x ∀ x ∈ [0, ∞)gₙ(x) → x ∀ x ∈ [0, ∞)
  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: (A) gₙ → 0 pointwise but not uniformlygₙ → 0 बिंदुवार लेकिन एकसमानतः नहीं

Explanation

For fixed x the limit is 0, but gₙ(1/n) = 1/2 for every n, so the sup-norm does not tend to 0. Hence convergence is pointwise only.स्थिर x के लिए सीमा 0 है, परंतु प्रत्येक n के लिए gₙ(1/n) = 1/2 है, अतः अधिकतम अंतर 0 की ओर नहीं जाता। इसलिए अभिसरण केवल बिंदुवार है।

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

This is question 76 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.