English

A Parallelopiped is Formed by Planes Drawn Through the Points (2, 3, 5) and (5, 9, 7), Parallel to the Coordinate Planes. the Length of Diagonal of the Parallelopiped is (A) 7 `Sqrt(38)` `Sqrt(155)`

Advertisements
Advertisements

Question

A parallelopiped is formed by planes drawn through the points (2, 3, 5) and (5, 9, 7), parallel to the coordinate planes. The length of a diagonal of the parallelopiped is

Options

  • 7

  • `sqrt(38)`

  • `sqrt(155)`

  • none of these

MCQ
Advertisements

Solution

7  

\[\text{ The given points } \left( 2, 3, 5 \right) \text{ and } \left( 5, 9, 7 \right) \text{ are two diagonally opposite vertices of the parallelopiped as all of their coordinates are different }. \]

\[ \therefore \text{ Edges of the parallelopiped } = \left| 2 - 5 \right|, \left| 3 - 9 \right| \text{ and } \left| 5 - 7 \right| \]

\[ = 3, 6 \text{ and } 2\]

\[\text { Now} , \]

\[\text{ Length of the diagonal of the parallelopiped } = \sqrt{\left( 3 \right)^2 + \left( 6 \right)^2 + \left( 2 \right)^2}\]

\[ \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} = \sqrt{9 + 36 + 4}\]

\[ \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} = \sqrt{49} \]

\[ \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} \hspace{0.167em} = 7\]

\[\text{ Hence, length of the diagonal of the parallelopiped formed by the planes parallel to coordinate planes and drawn through points }  \left( 2, 3, 5 \right) \text { and }  \left( 5, 9, 7 \right) \text{ is 7 units } . \]

 

shaalaa.com
  Is there an error in this question or solution?
Chapter 26: Direction Cosines and Direction Ratios - MCQ [Page 25]

APPEARS IN

R.D. Sharma Mathematics Volume 1 and 2 [English] Class 12
Chapter 26 Direction Cosines and Direction Ratios
MCQ | Q 4 | Page 25

RELATED QUESTIONS

Write the direction ratios of the following line :

`x = −3, (y−4)/3 =( 2 −z)/1`


Find the direction cosines of a line which makes equal angles with the coordinate axes.


Find the Direction Cosines of the Sides of the triangle Whose Vertices Are (3, 5, -4), (-1, 1, 2) and (-5, -5, -2).


If l1, m1, n1 and l2, m2, n2 are the direction cosines of two mutually perpendicular lines, show that the direction cosines of the line perpendicular to both of these are m1n2 − m2n1, n1l2 − n2l1, l1m2 ­− l2m1.


If a line makes angles of 90°, 60° and 30° with the positive direction of x, y, and z-axis respectively, find its direction cosines


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


Using direction ratios show that the points A (2, 3, −4), B (1, −2, 3) and C (3, 8, −11) are collinear.


Find the direction cosines of the sides of the triangle whose vertices are (3, 5, −4), (−1, 1, 2) and (−5, −5, −2).


Find the acute angle between the lines whose direction ratios are proportional to 2 : 3 : 6 and 1 : 2 : 2.


If the coordinates of the points A, B, C, D are (1, 2, 3), (4, 5, 7), (−4, 3, −6) and (2, 9, 2), then find the angle between AB and CD.


What are the direction cosines of Z-axis?


Write the coordinates of the projection of point P (x, y, z) on XOZ-plane.


Answer each of the following questions in one word or one sentence or as per exact requirement of the question:
Write the distance of a point P(a, b, c) from x-axis.


For every point P (x, y, z) on the xy-plane,

 


A rectangular parallelopiped is formed by planes drawn through the points (5, 7, 9) and (2, 3, 7) parallel to the coordinate planes. The length of an edge of this rectangular parallelopiped is


Ratio in which the xy-plane divides the join of (1, 2, 3) and (4, 2, 1) is


The angle between the two diagonals of a cube is


 

 


If a line makes angles α, β, γ, δ with four diagonals of a cube, then cos2 α + cos2 β + cos2γ + cos2 δ is equal to


Verify whether the following ratios are direction cosines of some vector or not

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


Find the direction cosines of a vector whose direction ratios are
0, 0, 7


Find the direction cosines and direction ratios for the following vector

`3hat"i" + hat"j" + hat"k"`


Find the direction cosines and direction ratios for the following vector

`5hat"i" - 3hat"j" - 48hat"k"`


A triangle is formed by joining the points (1, 0, 0), (0, 1, 0) and (0, 0, 1). Find the direction cosines of the medians


Choose the correct alternative:
The unit vector parallel to the resultant of the vectors `hat"i" + hat"j" - hat"k"` and `hat"i" - 2hat"j" + hat"k"` is


If the direction ratios of a line are 1, 1, 2, find the direction cosines of the line.


A line makes equal angles with co-ordinate axis. Direction cosines of this line are ______.


If a variable line in two adjacent positions has direction cosines l, m, n and l + δl, m + δm, n + δn, show that the small angle δθ between the two positions is given by δθ2 = δl2 + δm2 + δn2 


O is the origin and A is (a, b, c). Find the direction cosines of the line OA and the equation of plane through A at right angle to OA.


If the directions cosines of a line are k,k,k, then ______.


If a line makes angles 90°, 135°, 45° with x, y and z-axis respectively then which of the following will be its direction cosine.


The Cartesian equation of a line AB is: `(2x - 1)/2 = (y + 2)/2 = (z - 3)/3`. Find the direction cosines of a line parallel to line AB.


Equation of line passing through origin and making 30°, 60° and 90° with x, y, z axes respectively, is ______.


Equation of a line passing through point (1, 2, 3) and equally inclined to the coordinate axis, is ______.


Find the coordinates of the foot of the perpendicular drawn from point (5, 7, 3) to the line `(x - 15)/3 = (y - 29)/8 = (z - 5)/-5`.


In the relation between direction ratios and direction cosines, what does the sign \[\pm\] in \[l=\pm\frac{a}{\sqrt{a^2+b^2+c^2}}\] depend on?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×