Question 100Asked in BPSC TRE 2.0 (2023) Mathematics and Science Class 6-8

If p and q are the lengths of the perpendiculars drawn from the origin on the linesयदि रेखाओं

If p and q are the lengths of the perpendiculars drawn from the origin on the lines x sin θ + y cos θ = 2b sin θ cos θ x cos θ − y sin θ = b cos 2θ respectively, then the value of p² + q² is
यदि रेखाओं x sin θ + y cos θ = 2b sin θ cos θ x cos θ − y sin θ = b cos 2θ पर मूलबिन्दु से डाले गए लम्बों की लम्बाइयाँ क्रमशः p और q हों, तो p² + q² का मान है
  1. Ab²b²
  2. B1/b²1/b²
  3. C2b²2b²
  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) b²b²

Explanation

The distances from the origin are p = |2b sin θ cos θ| = b|sin 2θ| and q = b|cos 2θ|, so p² + q² = b²(sin²2θ + cos²2θ) = b².मूलबिन्दु से दूरियाँ p = |2b sin θ cos θ| = b|sin 2θ| और q = b|cos 2θ| हैं, अतः p² + q² = b²(sin²2θ + cos²2θ) = b²।

From BPSC TRE 2.0 (2023) Mathematics and Science Class 6-8 — Previous Year Paper

This is question 100 of BPSC TRE 2.0 (2023) Mathematics and Science Class 6-8 — 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.