Total derivative

Imagine you are playing with blocks, and you arrange them in a specific way. Now, you want to change the arrangement of the blocks, but you don't know how. So, you ask an adult for help.

The adult tells you that if you move one block, it may affect the position of other blocks. This is similar to what happens when you take the total derivative of a function.

A function is like a set of blocks that are arranged in a certain way. If you change one part of the function, the whole function can change. The total derivative is a way of measuring how much the function changes when you make a small adjustment to one part of it.

It's like taking apart the function block by block, and then putting it back together in a slightly different way. The total derivative tells you exactly how the function changes when you do this.

So, just like when you arrange blocks, the total derivative helps you understand how one part of a function affects the whole thing.