What type of graph represents a constant rate of change?

A linear graph is the representation of a constant rate of change. In mathematics, a linear graph depicts a straight line, which indicates that for every unit change in one variable, there is a consistent, proportional change in another variable. This relationship is characterized by a constant slope, which signifies that the change remains uniform across the entire range of the graph.

For instance, in the equation of a straight line (y = mx + b), 'm' represents the slope or the rate of change. If 'm' is constant, the rate at which 'y' changes concerning 'x' does not vary, leading to a straight line on the graph. This constancy is crucial in various real-world applications, such as speed and cost calculations.

In contrast, exponential, quadratic, and circular graphs depict relationships where the rates of change are not constant. Exponential graphs showcase rapid growth or decay; quadratic graphs represent a parabolic curve with varying slopes, and circular graphs illustrate periodic relationships that do not have a constant rate of change. Thus, the linear graph stands out as the only one that consistently represents a constant rate, making it the correct answer.