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If cos alpha, cos beta, gamma are direci...

If cos `alpha, cos beta, gamma` are direciton cosines then `cos 2 alpha + cos 2 beta + cos 2 gamma` = ................

A

`-1`

B

`0`

C

`4`

D

`3`

Text Solution

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The correct Answer is:
A
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KUMAR PRAKASHAN-THREE DIMENSIONAL GEOMETRY-MULTIPLE CHOICE QUESTIONS (MCQs)
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  2. The distance ratio of two lines are (5,-12,13) and (-3,4,5) . Then the...

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  3. If cos alpha, cos beta, gamma are direciton cosines then cos 2 alpha +...

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  4. A line makes an angle alpha,beta and gamma with axes repectively, The ...

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  5. The angle between the lines 2x = 3y = -z and 6x = -y = -4x is ...........

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  6. Givne lines are (x-1)/(l) = (y + 1)/(m) = z/n and (x+1)/(m) = (y-3)/...

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  7. The distance of the point P(1,2,3) from the line (x-6)/(3) = (y-7)/(2)...

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  8. The lines x/1 = y/2 = z/3 and (x-1)/(-2) = (y-2)/(-4) = (z-3)/(-6)are ...

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  9. The direction ratios of the line x-y+z-5=0=x-3y-6 are

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  10. The shortest distance the lines (x-3)/(3) = (y-8)/(-1) = (z-3)/(1) and...

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  11. The direction cosines of line satisfy the relations lambda(l+m) = n an...

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  12. The coordinates of a point on the line (x-1)/(2) = (y+1)/(-3) =z at a ...

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  13. The symmetric from of the equation of the line x + y -z = 1 and 2x -3y...

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  14. The direction ratios of there lines are (1,1,2),(3sqrt(3) - 1,sqrt(3) ...

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  15. If the lines (x-2)/(1) = (y-3)/(1) = (4-z)/(lambda) and (x-1)/(lambda)...

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  16. The image of the point (1,6,3) with respect to the line (x)/(1) = (y-1...

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  17. The distance of the point P(-2,3,1) from the line harr(QR) through Q(-...

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  18. If the lines 2x-y+3z + 4 = 0=ax + y-z + 2 and x-3y + z=0 =x + 2y + z +...

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  19. The distance of the plane barr (12,-4,3) = 65 from the origin is ........

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  20. The plane 2x - 3y + 6z + 9 =0 makes an angle with positive direciton o...

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