If ` vec a+ vec b+ vec c= vec0` , show that the angle `theta` between the vectors ` vec b` and ` vec c` is given by `costheta=(| vec a|^2-|b|^2-| vec c|^2)/(2| vec b|| vec c|)`

If vec a+vec b+vec c=vec 0, show that the angle theta between the vectors vec b and vec c ig givne by cos theta=(|vec a|-|vec b|-|vec c|)/(2|vec b||vec c|)

If |vec a|+|vec b|=|vec c| and vec a+vec b=vec c, then find the angle between vec a and vec b

If vec a + vec b = vec c and | vec a | = | vec b | = | vec c | find the angle between vec a and vec b

If vec a,vec b,vec c are three vectors such that vec a=vec b+vec c and the angle between vec b and vec c is (pi)/(2), then

If |vec a|=3,|vec b|=5,|vec c|=7 and vec a+vec b+vec c=0 then angle between vec a and vec b is

If vec a,vec b and vec c be any three vectors then show that vec a+(vec b+vec c)=(vec a+vec b)+vec c

vec a + vec b + vec c = vec 0, | vec a | = 3, | vec b | = 5, | vec c | = 7 then angle between vec a and vec b is

If vec a,vec b, and vec c are three vectors such that vec a xxvec b=vec c,vec b xxvec c=vec a,vec c xxvec a=vec b then prove that |vec a|=|vec b|=|vec c|

Let vec a, vec b, vec c are three vectors such that vec a * vec a = vec b * vec b = vec c * vec c and | vec a-vec b | ^ (2) + | vec b-vec c | ^ (2) + | vec c-vec a | ^ (2) = 27 then

If vec a,vec b, and vec c are unit vectors such that vec a+vec b+vec c=0, then find the value of vec a*vec b+vec b*vec c+vec c*vec a