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Tamil Nadu Board of Secondary EducationHSC Science Class 11

Find the direction cosines and direction ratios for the following vector iki^-k^

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Question

Find the direction cosines and direction ratios for the following vector

`hat"i" - hat"k"`

Sum
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Solution

The direction ratios of the vector `hat"i" + 0hat"j" - hat"k"` are (1, 0, – 1)

The direction cosines of the vector `hat"i" + 0hat"j" - hat"k"` are

`1/sqrt(1^2 + 0^2 + (-1)^2), 0/sqrt(1^2 + 0^2 + (-1)^2), (-1)/sqrt(1^2 + 0^2 + (-1)^2)`

`1/sqrt(1 + 0 + 1), 0/sqrt(1 + 0 + 1), (-1)/sqrt(1 + 0 + 1)`

`(1/sqrt(2), 0, (-1)/sqrt(2))`

DIrection ratios = (1, 0, – 1)

Direction cosines = `(1/sqrt(2), 0, (-1)/sqrt(2))`

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Chapter 8: Vector Algebra - Exercise 8.2 [Page 68]

APPEARS IN

Samacheer Kalvi Mathematics - Volume 1 and 2 [English] Class 11 TN Board
Chapter 8 Vector Algebra
Exercise 8.2 | Q 3. (vi) | Page 68

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