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

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

A line AB in three-dimensional space makes angles 45^o and 120^o with the positive x-axis and the positive y-axis respectively. If AB makes an acute angle θ with the positive z-axis, then θ equals

A straight line which makes an angle of 60^o with each of y and z-axes, this line makes with x-axes at an angle

What are the DR's of vector parallel to ( 2 , -1 , 1) and ( 3, 4 , -1 ) ?

If the direction cosines of two lines are such that l + m + n = 0, l² + m²-n² = 0, then the angle between them is

If the direction cosines of a line are, then

The xy - plane divides the line joining the points (-1,3,4) and (2,-5,6)

Let O be the origin and P be the point at a distance 3 units from origin.If direction ratios of OP are (1,-2,-2) then coordinates of P is given by

If projection of a line on x, y and z-axes are 6,2 and 3 respectively, then direction cosines of the line is