(a) A vector a is made of horizontal and vertical components a1i and a2j. (b) Top: The vector a has been multiplied by a factor of 2 with components 2a1i and 2a2j. Bottom: The vector a has been multiplied by a factor of 1/2 with components 1/2a1i and 1/2a2j. (c) As in b but the factor by which the vector has been scaled is negated resulting in a change of direction.