A. a,b,c

B. c,b,a

C. b,a,c

D. b,c,a

The fourth vertex of the parallelogram whose consecutive vertices are (2,4,-1), (3,6,-1),(4,5,1) is

If the points (3,2,-4) ,(5,4,k), (9,8,-10) are collinear then k=

The locus of a point P such that PA+PB=4 where A=(2,3,4) ,B=(-2,3,4) is

If the orthocenter and the circumcentre of a triangle are (-3,5,2), (6,2,5) then its centroid is

The ends of the hypotenuse of a right angled triangle are (2,0,-3), (0,4,1) then the locus of the third vertex is