Question 96Asked in BPSC TRE 1.0 (2023) Mathematics Class 11-12

The equation of the normal to the ellipse x²/a² + y²/b² = 1 at the point (a cos θ, b sin θ) isदीर्घवृत्त x²/a² + y²/b² = 1 के बिन्दु (a cos θ, b sin θ) पर अभिलम्ब का समीकरण है

दीर्घवृत्त x²/a² + y²/b² = 1 के बिन्दु (a cos θ, b sin θ) पर अभिलम्ब का समीकरण है
  1. Aax sec θ − by cosec θ = a² + b²ax sec θ − by cosec θ = a² + b²
  2. Bax cosec θ − by sec θ = a² − b²ax cosec θ − by sec θ = a² − b²
  3. Cax sec θ − by cosec θ = a² − b²ax sec θ − by cosec θ = a² − b²
  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) ax sec θ − by cosec θ = a² − b²ax sec θ − by cosec θ = a² − b²

Explanation

The normal at (x₁, y₁) is a²x/x₁ − b²y/y₁ = a² − b². With x₁ = a cos θ and y₁ = b sin θ this becomes ax sec θ − by cosec θ = a² − b².(x₁, y₁) पर अभिलम्ब a²x/x₁ − b²y/y₁ = a² − b² है। x₁ = a cos θ और y₁ = b sin θ रखने पर यह ax sec θ − by cosec θ = a² − b² हो जाता है।

From BPSC TRE 1.0 (2023) Mathematics Class 11-12 — Previous Year Paper

This is question 96 of BPSC TRE 1.0 (2023) Mathematics Class 11-12 — 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.