What is an application of derivatives in real life?

Derivatives help us measure how things change, so they're widely used in real life. For example, in business, companies use derivatives to find the point where they make the most profit by studying how revenue and costs change. In medicine, they help track how quickly a disease spreads. In physics, derivatives describe velocity and acceleration. Even in everyday activities like driving, your speedometer shows the derivative of your position—it tells how fast you’re going at any moment. These examples show that derivatives are not just abstract math—they’re practical tools for understanding and improving real-world systems.