Skill: Plot points in all four quadrants

The coordinate plane has two number lines:

• The horizontal line is the $x$-axis.
• The vertical line is the $y$-axis.
• Their intersection is the origin, $((0,0))$.

An ordered pair is written as $((x,y))$. The first number tells how far to move left or right. The second number tells how far to move up or down.

The signs tell you the quadrant:

Signs of $((x,y))$	Quadrant
$((+,+))$	I
$((-,+))$	II
$((-,-))$	III
$((+,-))$	IV

If a coordinate is $0$, the point is on an axis instead of in a quadrant.

Worked example: Plot $(A(-3,2))$

1. Start at the origin, $((0,0))$.
2. Look at the $x$-coordinate, $(-3)$. Move 3 units left.
3. Look at the $y$-coordinate, $2$. From there, move 2 units up.
4. Mark the point and label it $A$.

Because the $x$-coordinate is negative and the $y$-coordinate is positive, $(A(-3,2))$ is in Quadrant II.

Remember to use the coordinates in order. The point $((-3,2))$ is not the same as $((2,-3))$: reversing the numbers changes the point’s location.