ELI5: Explain Like I'm 5

Local linearization method

The local linearization method is like using a ruler to estimate a new number that is very close to the original number.

Imagine you have a very complicated function that is difficult to work with. If you want to find the value of this function at a specific point, you could use the local linearization method.

First, you choose a point very close to the point you want to find the value at. Then, you draw a straight line that is tangent to the function at that point. This line will be very close to the shape of the function near that point.

Next, you use the equation of that line – which is much easier to work with – to estimate the value of the function at the point you are interested in.

Think of it like estimating the height of a tree by standing right next to it and using a ruler to measure how far up the trunk you can reach. You know that the tree gets taller as you go up, so you estimate the height by assuming that the tree grows straight up from where you are measuring.

In the same way, the local linearization method helps simplify a complicated function by assuming that it behaves like a straight line near a specific point. This makes it much easier to work with the function and estimate its value at nearby points.