[" 17."4fa" a: "b=7:9" ant "b:c=15:7vec e" ,it a: "C" and "vec c" ? "],[[" (a) "5:3," (b) "7:21],[" (c) "3:5," (d) "7:15]]

[vec a + vec b, vec b + vec c, vec c + vec a] = 2 [vec a, vec b, vec c]

[vec a+vec b,vec b+vec c,vec c+vec a]=2[vec a,vec b,vec c]

Vectors vec(a), vec(b) and vec(c ) are such that vec(a) + vec(b) + vec(c ) = 0 and |vec(a)| = 3, |vec(b)| = 5 and |vec(c )| = 7 . Find the angle between vec(a) and vec(b) .

If vec(a) , vec(b) and vec(c ) be three vectors such that vec(a) + vec(b) + vec(c )=0 and |vec(a)|=3, |vec(b)|=5,|vec(C )|=7 , find the angle between vec(a) and vec(b) .

If vec a,vec b,vec c are vectors such that [vec a,vec b,vec c]=4 then [a xx b,b xx c,c xx a]=

Prove that vec(a)[(vec(b) + vec(c)) xx (vec(a) + 3vec(b) + 4vec(c))] = [ vec(a) vec(b) vec(c)]

[[vec a + vec b-vec c, vec b + vec c-vec a, vec c + vec a-vec b is equal to

If vec a, vec b and vec c are unit vectors satisfying | vec a-vec b | ^ (2) + | vec b-vec c | ^ (2) + | vec c-vec a | ^ (2) = 9 then | 2vec a + 7vec b + 7vec c | =

vec a+vec b+vec c=vec 0,vec |a|=3,|vec b|=5 and |vec c|=7 find the anglebetweeen vec a and vec b