ELI5: Explain Like I'm 5

Wallis' integrals

Wallis' integrals are a way for people to find the value of a certain type of math problem called an integral. Basically, an integral is like a bunch of tiny slices of pizza that you put together to figure out how much pizza you have in total.

Wallis' integrals work by using a special formula to figure out the value of an integral that looks a certain way. The formula has a bunch of letters and numbers in it, but it's basically a way of doing some fancy math that lets you find the answer to the problem.

This type of math can be really useful when you need to figure out things in science or engineering. Imagine you wanted to know how much water flows out of a pipe per second, or how much energy a certain machine uses. Using Wallis' integrals can help you figure out the answer to these kinds of questions.

So basically, Wallis' integrals are just a tool that smart people use to solve math problems with lots of little pieces, like slices of pizza. And people in science and engineering use them to answer important questions about how the world works.