A 2-dimensional vector may be expressed by
A = Ax i + Ay j
where i and j are unit vectors along the x (horizontal) and y (vertical) axes respectively.
Ax = horizontal part (x-component)
Ay = vertical part (y-component)
Alternatively, the vector may be written as
A = (Ax, Ay)
Answer:
Horizontal part = x-component
Vertical part = y-component