CBSE Class 12 Sample Paper for 2024 Boards

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Question 18 - CBSE Class 12 Sample Paper for 2024 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Last updated at August 10, 2026 by

If the direction cosines of a line are ⟨1/c,1/c,1/c⟩, then

(a) 0<c<1                          (b) c>2

(c) c=±√2                          (d) c=±√3

[MCQ] If the direction cosines of a line are <1/c, 1/c, 1/c>, then - CBSE Class 12 Sample Paper for 2024 Boards

part 2 - Question 18 - CBSE Class 12 Sample Paper for 2024 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

 

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Transcript

Given direction cosines of the line are š‘™ = 1/š‘ , m = 1/š‘ and n = 1/š‘ We know that š’^šŸ + š’Ž^šŸ + š’^šŸ = 1 (1/š‘)^2 +(1/š‘)^2+ (1/š‘)^2 = 1 3 (1/š‘)^2 = 1 (šŸ/š’„)^šŸ= šŸ/šŸ‘ 1/š‘ = Ā±āˆš(1/3) 1/š‘ = Ā± 1/āˆš3 c = Ā± āˆššŸ‘ So, the correct answer is (d)

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