(A) Definition of Vector and Vector Notation
1. Vector is a quantity that has both magnitude and direction.
2. Scalar is a quantity that has magnitude only.
3. A vector can be presented by a line segment with an arrow, known as a directed line segment.
(B) Equality of Two Vectors
1. Negative vector of has the same magnitude as but its direction is opposite to that of .
3. Two vectors are equal if both the vectors have the same magnitude and direction.