The midpoint rule, a numerical integration technique, provides an approximation of the definite integral of a function. It operates by dividing the area under a curve into a series of rectangles, where the height of each rectangle is determined by the function’s value at the midpoint of the rectangle’s base. Summing the areas of these rectangles yields an estimate of the total area, thus approximating the definite integral. For example, to approximate the integral of f(x) from a to b using four rectangles, the interval [a, b] is divided into four equal subintervals. The height of each rectangle is f(mi) where mi is the midpoint of the i-th subinterval.
This method offers a relatively simple and computationally efficient way to estimate definite integrals, particularly useful when an analytical solution is difficult or impossible to obtain. Its accuracy improves as the number of rectangles increases, providing a closer approximation to the true value of the integral. Historically, numerical integration methods like this were crucial before the advent of powerful computing tools, enabling mathematicians and scientists to perform complex calculations. Today, they remain valuable for handling intricate integrals and form the basis of more sophisticated numerical techniques.