[" If "A(x_(1),y_(1),z_(1)),B(x_(2),y_(2),z_(2))" then the projection of "],[vec AB" on y-axis is "]

Assertion (A): A(x_(1),y_(1),z_(1)), B(x_(2),y_(2),z_(2)) . The projection of AB on the line with D.C's (l,m,n) is l(x_(2)-x_(1)) +m(y_(2)-y_(1))+n(z_(2)-z_(1)) Reason (R ) : The projection of the join of A (x_(1),y_(1),z_(1)), B(x_(2),y_(2),z_(2)) on yz plane is sqrt((y_(2)-y_(1))^(2)+(z_(2)-z_(1))^(2))

A (x_(1),y_(1),z_(1)), B(x_(2),y_(2),z_(2)) are two points. Then the lenghts of projection on

The A={x_(1),y_(1),z_(1)} and B={x_(2),y_(2)}, then the number of relations from A to B is

ZX-Plane divides the line joining A(x_(1),y_(1),z_(1)),B(x_(2),y_(2),z_(2)) in the ratio =

If A = {x_(!) , y_(1), z_(1)} and B = {x_(2), y_(2)} , then the number of relations from A to B is

If A = {x_(!) , y_(1), z_(1)} and B = {x_(2), y_(2)} , then the number of relations from A to B is

Let A(x_(1),y_(1),z_(1)),B(x_(2),y_(2),z_(2))&C(x_(3),y_(3),z_(3)) be the vertices of triangle ABC Let D,E and F be the midpoints of BC,AC&AB respectively Show that centroids of ABC&Delta DEF coincides.

If D(x_(1),y_(1),z_(1)), E(x_(2),y_(2),z_(2)) and F(x_(3),y_(3),z_(3)) are the midpoints of the sides BC, CA and AB respectively of a triangle, find its vertices A, B and C.

The line segment joining A(x_(1),y_(1),z_(1)),B(x_(2),y_(2),z_(2)) is divided by XY - plane in the ratio

If (x_(1),y_(1),z_(1)),(x_(2),y_(2),z_(2)) and (x_(3),y_(3),z_(3)) are the vertices of an equilateral triangle such that (x_(1)-2)^(2)+(y_(1)-3)^(2)+(z_(1)-4)^(2)=(x_(2)-2)^(2)+(y_(2)-3)^(2)+(z_(2)-4)^(2) =(x_(3)-2)^(2)+(y_(3)-3)^(2)+(z_(3)-4)^(2) then sum x_(1)+2sum y_(1)+3sum z_(1)