Skill: Identify coordinates of points in all four quadrants

To identify the coordinates of a point, start at the origin, $(0,0)$.

1. Read the horizontal movement first. This is the $x$-coordinate:
   • right: positive
   • left: negative
2. Read the vertical movement second. This is the $y$-coordinate:
   • up: positive
   • down: negative
3. Write the coordinates as an ordered pair, $(x,y)$.

The signs tell you the quadrant:

• Quadrant I: $(+,+)$
• Quadrant II: $(-,+)$
• Quadrant III: $(-,-)$
• Quadrant IV: $(+,-)$

Example

Point $A$ is 4 units left of the origin and 3 units down.

• Moving 4 units left gives $x=-4$.
• Moving 3 units down gives $y=-3$.
• Write $x$ first and $y$ second:

$$A=(-4,-3)$$

Both coordinates are negative, so point $A$ is in Quadrant III.

If a point lies directly on an axis, one coordinate is $0$. For example, a point 5 units right of the origin is $(5,0)$ and is not in a quadrant.