If `a, b, c` be three units vectors such that ` a xx (b xx c)=(1/2) b ; b and c` being non-parallel then

If a,b,c are three unit vectors such that a xx (b xx c) = (1)/(2) b then the angles between a,b and a,c are

If vec a,vec b,vec c are three unit vectors such that vec a xx(vec b xxvec c)=(1)/(2)(vec b+vec c). If the vectors vec b and vec c are non-parallel,then the angle between vec a and vec b is

If vec a,vec b, and vec c are non-coplanar unit vectors such that vec a xx(vec b xxvec c)=(vec b+vec c)/(sqrt(2)),vec b and vec c are non parallel,then prove that the angel between vec a and vec b is 3 pi/4

If hat(a),hat(b),hat(c) are three unit vectors such that hat(b)andhat(c) are non-parallel and hat(a)xx(hat(b)xxhat(c))=(1)/(2)hat(b)," find the angle between "vec(a)andvec(c).