Define collinear vectors.

a and b are non-collinear vectors. If c=(x-2) a+b and d=(2x+1)a-b are collinear vectors, then find the value of x.

Let vec a and vec b be two non collinear unit vectors. If vec u = vec a - (vec a . vec b) vec b and vec nu = vec a xx vec b , then |vec nu| =

Answer the followings true or false. (i) vecaand-veca are collinear. (ii) Two collinear vectors are always equal in magnitude. (iii) Two vectors having same magnitude are collinear. (iv) Two collinear vectors having the same magnitude are equal.

If a and b are two non-zero and non-collinear vectors then a+b and a-b are

If a and b are two non collinear vectors; then every vector r coplanar with a and b can be expressed in one and only one way as a linear combination: xa+yb=0.

If vecx and vecy are two non-collinear vectors and ABC is a triangle with side lengths a, b and c satisfying (20a - 15b) vecx + ( 15b - 12c) vecy+ (12c - 20 a) (vecx xx vecy) = vec0 , then triangle ABC is

If the points P(vec a + 2 vec b + vec c), Q (2 vec a + 3 vec b), R(vec b + t vec c) are collinear, where vec a, vec b, vec c are three non-coplanar vectors, the value of t is

Let a,b,c are three vectors of which every pair is non-collinear, if the vectors a+b and b+c are collinear with c annd a respectively, then find a+b+c.