Three Dimension...

If $$AB=21,\ B\equiv (-2,1,-8)$$ and the direction cosines of $$AB$$ are $$\dfrac{6}{7},\dfrac{2}{7},\dfrac{3}{7}$$ then the coordinates of $$A$$ are

If from the point $$P ( f , g , h )$$ perpendiculars $$PL , PM$$ be drawn to $$y z$$ and $$zx$$ planes then the equation to the plane $$OLM$$ is -

If the d.c's of two lines are such that $$l+3m+n=0,{ 3l }^{ 2 }+{ 5m }^{ 2 }-{ 4n }^{ 2 }=0$$, then the angle between them is 

If the angle between the lines, $$\dfrac { x }{ 2 } =\dfrac { y }{ 2 } =\dfrac { z }{ 1 } $$ and $$\dfrac { 5-x }{ -2 } =\dfrac { 7y-14 }{ P } =\dfrac { z-3 }{ 4 } $$ is $$\cos { ^{ -1 }\left( \dfrac { 2 }{ 3 }  \right)  } $$, then p is equal to: 

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:- 

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

If $$(2,1,3)$$ and $$(-1,2,4)$$ are the extermities of a diagonal of a rhombus then the $$d.r's$$ of the other diagonal are

A mirror and source of light are kept at the origin and the positive x-axis respectively a ray a light from the sources strikes the mirror and is reflected. If (1,-1,1) are the Dr's of a normal to the plane. Then the D.C's of the reflected ray are 

If the incident ray and normal have the directions of the vectors $$\left(1,-3,1\right),\left(1,1,1\right)$$ respectively, then direction of the reflected ray is-

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:-