To find the rate of change (slope) of the function from the graph, we can use the formula for the slope:

$\text{slope} = \frac{\Delta y}{\Delta x} = \frac{y_2 - y_1}{x_2 - x_1}$

From the graph, let's pick two points on the line:

1. Point 1: $(-5, -5)$
2. Point 2: $(5, 5)$

Using these points:

$\text{slope} = \frac{5 - (-5)}{5 - (-5)} = \frac{10}{10} = 1$

So, the rate of change of the function is $1$.

Would you like further details or have any questions?

Here are some additional related questions:

1. What is the equation of a line with a slope of 1 and passing through the origin?
2. How would you identify the slope if the line was steeper or flatter?
3. What would be the slope if the line was decreasing instead of increasing?
4. How do you find the y-intercept from a graph?
5. Can a vertical line have a slope?

Tip: The rate of change for a linear function corresponds to the "steepness" of the line and is consistent throughout the line.