ELI5: Explain Like I'm 5

Newton's method in optimization

Imagine you have a toy car that you want to move from one point to another but you cannot see where the end point is. You only know that there is a way to reach the end point and you want to get there as quickly as possible. Newton's method in optimization is like having a smart friend who helps you figure out the best way to move the toy car so that it gets closer to the end point with each move.

Newton's method is a mathematical process that can be used to find the minimum or maximum value of a function. It is especially useful in cases where the function is complicated or has many variables. The method works by starting with an initial guess for the minimum or maximum value and then repeatedly refining this guess until it gets as close to the actual value as possible.

To apply Newton's method to our toy car problem, we can think of the distance between the current position of the car and the end point as the function we want to optimize. Our friend, using Newton's method, would start by taking the current position of the car and calculating the slope of the curve that represents the distance function at that point. The slope tells us which direction the car should move to get closer to the minimum value of the function, which in this case is the end point.

Then, our friend would calculate how far the car should move in this direction to make the greatest progress in getting closer to the end point. This is done using a formula called the Newton-Raphson formula. Our friend would move the toy car by this amount and check the new position to see if it is closer to the end point than the previous position. If it is, then our friend would repeat the process with the new position.

This process of calculating the slope, moving the car, and checking the new position is repeated over and over again until the car reaches the end point. At each step, the car gets closer and closer to the end point until it finally reaches it.

In summary, Newton's method in optimization is a mathematical process that helps find the minimum or maximum value of a function by repeatedly refining an initial guess. It is like having a smart friend who can tell us which direction to move in to get closer to our goal and how far to move in that direction. It can be used to solve complex problems, like finding the best route for a car to take or optimizing the design of a product.