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एक रेखा की दिक्-कोसाइन ज्ञात कीजिए तो न...

एक रेखा की दिक्-कोसाइन ज्ञात कीजिए तो निर्देशांक्षो के साथ समान कोण बनाती है |

A

`(1/3, 1/3, 1/3)`

B

`(1/sqrt(3),1/sqrt(3),1/sqrt(3))`

C

`(1/sqrt(3),1/(3),1/(3))`

D

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

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The correct Answer is:
**Step-by-Step Solution:** 1. **Understanding Direction Cosines**: Direction cosines of a line are the cosines of the angles that the line makes with the coordinate axes. If a line makes angles α, β, and γ with the x, y, and z axes respectively, then the direction cosines are given by cos(α), cos(β), and cos(γ). 2. **Given Condition**: The problem states that the line makes equal angles with the coordinate axes. This means that α = β = γ. 3. **Using the Property of Direction Cosines**: Since the angles are equal, we can denote them as α. Therefore, we have: - cos(α) = cos(β) = cos(γ) 4. **Relation of Direction Cosines**: The sum of the squares of the direction cosines is equal to 1: \[ \cos^2(α) + \cos^2(β) + \cos^2(γ) = 1 \] Since cos(α) = cos(β) = cos(γ), we can denote this common value as 'l'. Thus, we can write: \[ 3l^2 = 1 \] 5. **Solving for l**: From the equation \(3l^2 = 1\), we can solve for l: \[ l^2 = \frac{1}{3} \] \[ l = \pm \frac{1}{\sqrt{3}} \] 6. **Conclusion**: Therefore, the direction cosines of the line that makes equal angles with the coordinate axes are: \[ \cos(α) = \cos(β) = \cos(γ) = \pm \frac{1}{\sqrt{3}} \]
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AAKASH INSTITUTE ENGLISH-THREE DIMENSIONAL GEOMETRY -ASSIGNMENT SECTION - A
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  2. The equation of the plane passing through the intersection of x + 2y +...

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  3. A unit vector normal to the plane through the points hati, 2hatj and...

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  4. The direction cosines of the normal to the plane x + 2y - 3z + 4 = 0...

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  5. The two lines x=ay+b,z=cy+d and x=a'y+b', z=c'y +d' are pendicular to ...

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  6. The angle between the line whose d.c.'s are connected by the relations...

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  7. Find the coordinates of the foot of perpendicular drawn from th poi...

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  9. The number of unit vectors perpendicular to the plane of vectors veca=...

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  10. The pair of lines whose direction cosines are given by the equations 3...

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  11. If direction cosines of a line are (1/a, 1/a, 1/a) then

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  14. Find the equation of the plane passing through the point (-1, 3, 2) an...

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