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If a Line Has Direction Ratios 2, −1, −2, Determine Its Direction Cosines. - Mathematics

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प्रश्न

If a line has direction ratios 2, −1, −2, determine its direction cosines.

बेरीज

उत्तर

 

\[\text{Let the direction cosines of the line be l, m, n .} \]

\[\text{ Now,} \]

\[ l = \frac{2}{\sqrt{2^2 + \left( - 1 \right)^2 + \left( - 2 \right)^2}} = \frac{2}{3}\]\[m = \frac{- 1}{\sqrt{2^2 + \left( - 1 \right)^2 + \left( - 2 \right)^2}} = \frac{- 1}{3}\]\[n = \frac{- 2}{\sqrt{2^2 + \left( - 1 \right)^2 + \left( - 2 \right)^2}} = \frac{- 2}{3}\]\[\text{Therefore, the direction cosines of the line are }\frac{2}{3} , \frac{- 1}{3}, \frac{- 2}{3} .\]

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पाठ 27: Direction Cosines and Direction Ratios - Exercise 27.1 [पृष्ठ २३]

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आरडी शर्मा Mathematics [English] Class 12
पाठ 27 Direction Cosines and Direction Ratios
Exercise 27.1 | Q 2 | पृष्ठ २३

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