Vectors: Magnitude & Direction (I)

A vector is a mathematical quantity with both magnitude and direction. The magnitude of vector u, denoted |u|, is it's length. One way to express its direction is to give the angle it makes with a horizontal ray (that points to the right) that is parallel to the positive x-axis. This is called the vector's direction angle. See below. You can also change the locations of the vector's initial point and terminal point. KEY QUESTION: Given a vector's magnitude and direction, how can you rewrite this vector in component form? < , > ?