[" 12.If "vec DA=vec a,vec AB=vec b" and "vec CB=vec ka" where "k>0" and "X,Y" are the mid-points of "],[DB&AC" respectively,such that "|vec a|=17&|vec XY|=4," then "k" equal to - "]

Ifvec DA= vec a, vec AB = vec b and vec CB= k veca wherek gt0 and X,Y are the midpoints of DB & AC respectively, such that |vec a| = 17 & |vec XY| = 4, then k equal to

If vec(DA)=veca,vec(AB)=vecb and vec(CB)=kveca where kgt0 and X,Y are the midpoint of DB and AC respectively such that |veca|=17 and |vec(XY)|=4, then k is equal to (A) 9/17 (B) 8/17 (C) 25/17 (D) 4/17

If vec(DA)=veca,vec(AB)=vecb and vec(CB)=kveca where kgt0 and X,Y are the midpoint of DB and AC respectively such that |veca|=17 and |vec(XY)|=4, then k is equal to (A) 9/17 (B) 8/17 (C) 25/17 (D) 4/17

If vec a xx i+2vec a-4vec i-2vec j+vec k=0 then vec a=

If ABCD is quadrilateral and E and F are the mid-points of AC and BD respectively, prove that vec AB+vec AD+vec CB+vec CD=4vec EF

If vec a = i+j+k, vec a. vec b = 1 and vec a xx vec b = j-k then vec b =

If vec(a)=vec(OA) " and " vec(b)=vec(AB), " then " vec(a)+vec(b) is -

In quadrilateral ABCD,vec AB=vec a,vec BC=vec b,vec AD=vec b-vec a If M is the mid point of BC and N is a point on DM such that DN=(4)/(5)DM, then vec AN=

If ABCD is a quadrilateral and E and F are the midpoints of AC and BD respectively, then prove that vec(AB)+vec(AD)+vec(CB)+vec(CD)=4vec(EF) .

If vec a,vec b,vec c are the position vectors of points A,B,C and D respectively such that (vec a-vec d)*(vec b-vec c)=(vec b-vec d)*(vec c-vec a)=0 then D is the