1. **Problem:** Explain the 4 quadrants of the coordinate plane for **positive** and **negative** values. 2. **Formula/rule:** In the coordinate plane, a point is written as $ (x,y) $. The sign of $x$ tells left or right, and the sign of $y$ tells down or up. 3. **Important rules:** - $x>0$ means right. - $x<0$ means left. - $y>0$ means up. - $y<0$ means down. 4. **Quadrant I:** $x>0$, $y>0$. - Both coordinates are positive. - Example: $(3,4)$. 5. **Quadrant II:** $x<0$, $y>0$. - $x$ is negative and $y$ is positive. - Example: $(-3,4)$. 6. **Quadrant III:** $x<0$, $y<0$. - Both coordinates are negative. - Example: $(-3,-4)$. 7. **Quadrant IV:** $x>0$, $y<0$. - $x$ is positive and $y$ is negative. - Example: $(3,-4)$. 8. **Easy memory trick:** Start in Quadrant I and move counterclockwise: - I: $+,+$ - II: $-,+$ - III: $-,-$ - IV: $+,-$ 9. **Final answer:** - Quadrant I: positive, positive - Quadrant II: negative, positive - Quadrant III: negative, negative - Quadrant IV: positive, negative