Direction Cosines and Direction Ratios of a Line

IMPORTANT

Direction Cosines and Direction Ratios of a Line: Overview

This topic consists of various concepts like Line in 3D,Directions Cosines of a Line,Direction Cosines of a Line Joining Two Points, etc.

Important Questions on Direction Cosines and Direction Ratios of a Line

MEDIUM
IMPORTANT

Let P-2,-1,1 and Q5617, 4317, 11117 be the vertices of the rhombus PQRS. If the direction ratios of the diagonal RS are α,-1,β, where both α and β are integers of minimum absolute values, then α2+β2 is equal to 

EASY
IMPORTANT

If direction ratios of a line are λ, λ2-3,1 and it makes and angle of 60 with z-axis, then a value of y is ?

HARD
IMPORTANT

Anuj and Tara are flying kites from their rooftops. Anuj's kite's string is represented by a straight line, given by x-41=y-23=z-12. Tara's position is at 2i^-2j^+k^, and her kite's string is perpendicular to Anuj's. Find out how far Tara is from where the kite strings intersect. Show your work.

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MEDIUM
IMPORTANT

A line makes an angle of 135° with the positive direction of the x-axis, and an angle of 300° with the positive direction of the y-axis.   Which of the following could be the angle it makes with the negative direction of the z axis? 

MEDIUM
IMPORTANT

Write the direction cosines of the line, whose Cartesian equations are 6x12=3y+9=2z2.

EASY
IMPORTANT

If a=142i^+3j^+k^ then write the direction cosines of a ?

EASY
IMPORTANT

The direction ratios of a normal to the plane passing through (0,1,1),(1,1,2) and (1,2,2) are

HARD
IMPORTANT

A line is inclined at an angle α, β, γ with the positive direction of x, y, z axes respectively. If β+γ=π2, then the maximum possible value of cosα+sinβ+sinγ2 is equal to

MEDIUM
IMPORTANT

If 2,3,c are the direction ratios of a ray passing through the point C5,q,1 and also the mid point of the line segment joining the points Ap,-4.2 and B3,2,-4 then c.p+7q=

EASY
IMPORTANT

If a,b,c are the direction ratios of a line joining the points 4,3,-5 and -2,1,-8 then the point Pa,3 b,2c lies on the plane

EASY
IMPORTANT

If the direction ratios of a line are 1,-3,2, then the direction cosines of the line are

EASY
IMPORTANT

If the direction ratios a, b, c of a line L satisfy the relation ab+bc+ca=0 and 6ab+9bc+8ca=0, then the direction cosines of the line L are

MEDIUM
IMPORTANT

The point of intersection of the line passing through0,0,1 and intersecting the lines x+2y+z=1,-x+y-2z=2 and x+y=2, x+z=2 with xy plane is :

EASY
IMPORTANT

A particle is at a point A(1,0,1) and then moves to the point B(-1,1,1) then angle made by AB with positive direction of x-axis is

HARD
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A line makes angles α, β, γ and δ with the diagonals of a cube, prove that
cos2 α+cos2 β+cos2 γ+cos2 δ=43

EASY
IMPORTANT

Show that the points A2, 3,-4, B1,-2, 3 and C3, 8,-11 are collinear.

EASY
IMPORTANT

Find the direction cosines of x, y and z-axis.

MEDIUM
IMPORTANT

Find the direction cosines of the line passing through the two points -2, 4, -5 and 1, 2, 3

EASY
IMPORTANT

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

EASY
IMPORTANT

Find the direction cosines of the following line: 

3-x-1=2y-12=z4