मराठी

Find the angle between the following pairs of lines: x + 4 3 = y − 1 5 = z + 3 4 a n d x + 1 1 = y − 4 1 = z − 5 2

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प्रश्न

Find the angle between the following pair of line:

\[\frac{x + 4}{3} = \frac{y - 1}{5} = \frac{z + 3}{4} \text  { and }  \frac{x + 1}{1} = \frac{y - 4}{1} = \frac{z - 5}{2}\]

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उत्तर

\[\frac{x + 4}{3} = \frac{y - 1}{5} = \frac{z + 3}{4} and \frac{x + 1}{1} = \frac{y - 4}{1} = \frac{z - 5}{2}\]

Let

\[\overrightarrow{b_1}\] and \[\overrightarrow{b_2}\] be vectors parallel to the given line.

\[\overrightarrow{b_1}\] = 3 \hat{i} + 5 \hat{j} + 4 \hat{k} \]

\[\overrightarrow{b_2}\] = \hat{i} + \hat{j}+ 2 \hat{k} \]

If θ is the angle between the given line, then

\[\cos \theta = \frac{\overrightarrow{b_1} . \overrightarrow{b_2}}{\left| \overrightarrow{b_1} \right| \left| \overrightarrow{b_2} \right|}\]

\[ = \frac{\left( 3 \hat{i} + 5 \hat{j} + 4 \hat{k} \right) . \left( \hat{i} + \hat{j} + 2 \hat{k} \right)}{\sqrt{3^2 + 5^2 + 4^2} \sqrt{1^2 + 1^2 + 2^2}}\]

\[ = \frac{3 + 5 + 8}{10\sqrt{3}}\]

\[ = \frac{8}{5\sqrt{3}}\]

\[ \Rightarrow \theta = \cos^{- 1} \left( \frac{8}{5\sqrt{3}} \right)\]

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पाठ 27: Straight Line in Space - Exercise 28.2 [पृष्ठ १६]

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आर.डी. शर्मा Mathematics Volume 1 and 2 [English] Class 12
पाठ 27 Straight Line in Space
Exercise 28.2 | Q 9.1 | पृष्ठ १६

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