Understanding quadrants is important when looking at graphs, especially when we want to see how functions behave.

The Cartesian plane has four quadrants. Each quadrant is named by looking at the signs of the $x$ (horizontal) and $y$ (vertical) coordinates:

1. Quadrant I: Here, both $x$ and $y$ are positive. This means both values go up, which usually shows that function results are positive.

2. Quadrant II: In this quadrant, $x$ is negative, and $y$ is positive. This means that $x$ values go down, but $y$ values stay positive. So, functions in this area can show how something decreases while still being positive for $y$.

3. Quadrant III: Both $x$ and $y$ are negative in this quadrant. When functions enter this area, they show negative results, which helps us understand how certain equations work.

4. Quadrant IV: Here, $x$ is positive, while $y$ is negative. This can happen in real-life situations, like comparing profit and cost. Profit can be positive, while costs might show up as negative.

Knowing which quadrants a graph is in helps us understand how a function behaves, where it crosses the axes, and what its key points are. About 70% of the math we see in real life can be shown in these quadrants. That's why it's so important for solving problems and looking at data in year 11 math classes.