If `bar a=b`, `c in R`

If bar r=l(bar b xx bar c)+m(bar c xx bar a)+n(bar a xx bar b) and [bar a bar b bar c]=2 , then l+m+n is equal to

Let bar(a) =(1,1,-1), bar(b) =(5,-3,-3) and bar(c) =(3,-1,2). If bar(r) is collinear with bar(c) and has length (|bar(a)+bar(b)|)/(2) then bar(r)

Let bar(a)=-bar(i)-bar(k),bar(b)=-bar(i)+bar(j) and bar(c)=bar(i)+2bar(j)+3bar(k) be three given vectors. If bar(r) is a vector such that bar(r) times bar(b)=bar(c) times bar(b) and bar(r).bar(a)=0 then bar(r).bar(b)=

i) bar(a), bar(b), bar(c) are pairwise non zero and non collinear vectors. If bar(a)+bar(b) is collinear with bar(c) and bar(b)+bar(c) is collinear with bar(a) then find the vector bar(a)+bar(b)+bar(c) . ii) If bar(a)+bar(b)+bar(c)=alphabar(d), bar(b)+bar(c)+bar(d)=betabar(a) and bar(a), bar(b), bar(c) are non coplanar vectors, then show that bar(a)+bar(b)+bar(c)+bar(d)=bar(0) .

bar a, bar b, bar c are three vectros, then prove that: (bar a xx bar b) xx bar c = (bar a. bar c) bar b-(bar b. bar c) bar a.

(d) answer ANY one question :1. bar a, bar b and bar c be three vectors such that bar a +bar b+ bar c =0 and |bar a|=1, |bar b|=4,|bar c |=2 . Evlautae bar a.bar b + bar b.bar c+bar c.bar a .

The vector equation of the plane passing through the points bar(a), bar(b), bar(c)" is "bar(r)=alphabar(a)+betabar(b)+gammabar(c) provided

bar(a),bar(b) and bar( c ) are three non zero, non planar vectors. bar(p)=bar(a)+bar(b)-2bar( c ),bar(q)=3bar(a)-2bar(b)+bar( c ) and bar( r )=bar(a)-4bar(b)+2bar( c ) . The volume of the parallelepiped formed by the vectors bar(a),bar(b) and bar( c ) is V_(1) and the volume of the parallelepiped formed by the vectors bar(p),bar(q) and bar( r ) is V_(2) then V_(2):V_(1) = .............