What is the abscissa of any point on y-axis?

Let us assume a point A(x, y) on the coordinate plane, where:

• x = abscissa (the x-coordinate)
• y = ordinate (the y-coordinate)

Movement along the x-axis (left or right):

• When the point moves right, the x-value increases.
  Example: (2, 3) moved 1 unit right → (3, 3)
• When the point moves left, the x-value decreases.
  Example: (2, 3) moved 1 unit left → (1, 3)

Movement along the y-axis (up or down):

• When the point moves up, the y-value increases.
  Example: (2, 3) moved 1 unit up → (2, 4)
• When the point moves down, the y-value decreases.
  Example: (2, 3) moved 1 unit down → (2, 2)

Special case – Points on the y-axis:

• Any point on the y-axis is written as (0, y).
• If the point moves right or left, the x-value stays 0.
• If the point moves up or down, the y-value changes.

Therefore, the abscissa (x-coordinate) of any point on the y-axis is always 0.

Note: In such problems, always assume a point on the graph and check how the coordinates change when the point moves in different directions. For points on the y-axis, the abscissa always remains zero.