The direction cosines of the line which is perpendicular to the lines whose direction cosines are proportional to (1,-1,2) and (2,1,-1) are
None of these
If the direction cosines of a line are, then
0 < c< 1
c > 2
If a line makes angles ,β,Υ and with four diagonals of a cube, then the value of is
1
A straight line which makes an angle of 60o with each of y and z-axes, this line makes with x-axes at an angle
300
600
750
450
What are the DR's of vector parallel to ( 2 , -1 , 1) and ( 3, 4 , -1 ) ?
(1,5,-2)
(-2,-5,2)
(-1,5,2)
(-1,-5,-2)
Cosine of the angle between two diagonals of cube is equal to
2/√6
1/3
1/2
The xy - plane divides the line joining the points (-1,3,4) and (2,-5,6)
internally in the ratio 2 : 3
externally in the ratio 2 : 3
internally in the ratio 3 : 2
externally in the ratio 3 : 2
The vectors of magnitude a , 2a , 3a meet at a point and their directions are along the diagonals of three adjacent faces of a cube. Then, the magnitude of their resultant is
5a
6a
10a
9a
The perpendicular distance of the point (6,5,8) from y-axis is
5 units
6 units
8 units
10 units
A line makes an obstuse angle with the positive x-axis and angle with the positive y and z-axes respectively.
Its direction cosine are