A. 6

B. 3

C. 6

D. -3

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

The line joining the points (2,3,4) and (4,10,7) intersects the line joining(2,-1,5) and (4, -30,17). Then the coordinates of the point of intersection are

The circumradius of the triangle formed by the points (2,-1,1) , (1,-3,-5), (3,-4,-4) is