If `(4k_1, k_1^2, 1) and (4k_2, k_2^2, 1)` are two points lying on the plane in which `(2, 3, 2) and (1, 2, 1)` are mirror image to each other,then `k_1,k_2` is equal to

If (4k _(1), k _(2) ^(2) , 1) and ( 4k _(2) , k _(2) ^(2), 1) are two points lying on the plane in which (2,3,2) and (1,2,1) are mirror image to each other, then k _(1) k _(2) is equal to

If (2,k,-1) is the centroid of the triangle with vertices (2,-1,2) (1,-3,-4) and (3,k,-1), then k=

If the points (k,k),(2 , 3) and (4 , -1) are collinear then k = ........

If the value of k , is the points (k, 2-2k) , (1-k, 2k) and (-4-k, 6-2 k) are collinear.

If k,2k-1 and 2k+1 are in the arithmetic progression then k

If the value of K, is the points (k, 2-2k), (1-k, 2k) and (-4-k, 6-2 k) are collinear.

If (2,k,-1) is the centroid of the triangle with vertices (2,-1,2), (1,-3,4) and (3,k,-1) , then k= _____.