👉 In calculus, a subderivative is defined as an extension of a function's derivative to include only the values where the function is decreasing or increasing. This allows for understanding the behavior and changes in the graph of the function at specific points. A subderivative can be calculated by subtracting the original function from its derivative, which gives us a new function that represents the slope of the function as it approaches the point where it changes direction. The subderivative is then used to find local max
