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If a Line Has Direction Ratios Proportional to 2, −1, −2, Then What Are Its Direction Consines?

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प्रश्न

If a line has direction ratios proportional to 2, −1, −2, then what are its direction consines?

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उत्तर

\[\text { If a line has direction ratios proportional to 2, - 1, and - 2, then its direction cosines are } \]

\[ \frac{2}{\sqrt{\left( 2 \right)^2 + \left( - 1 \right) + \left( - 2 \right)^2}}, \frac{- 1}{\sqrt{\left( 2 \right)^2 + \left( - 1 \right) + \left( - 2 \right)^2}}, \frac{- 2}{\sqrt{\left( 2 \right)^2 + \left( - 1 \right) + \left( - 2 \right)^2}} \]

\[ = \frac{2}{3}, - \frac{1}{3}, - \frac{2}{3}\]

\[\text { Thus, the direction cosines are } \frac{2}{3}, - \frac{1}{3}, - \frac{2}{3} .\]

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अध्याय 26: Direction Cosines and Direction Ratios - Very Short Answers [पृष्ठ २५]

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आर.डी. शर्मा Mathematics Volume 1 and 2 [English] Class 12
अध्याय 26 Direction Cosines and Direction Ratios
Very Short Answers | Q 17 | पृष्ठ २५

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