ELI5: Explain Like I'm 5

Bhaskara I's sine approximation formula

Have you ever seen a circle? It's like a ball but flat, and it goes round and round. When you draw a line from the center of the circle to the edge, it's called a radius. The length of the radius depends on how big or small the circle is.

Now, the sine of an angle is a special relationship between the length of the radius and the distance from the center of the circle to a certain point on the edge of the circle, called the sine of that angle. It's a little confusing, but it's important to remember that the sine is just a way of figuring out how much a line is bent from straight, and it helps us solve math problems.

Bhaskara i was a very smart man who lived a long time ago. He figured out a way to get a really good approximation, or estimate, of the sine of an angle without having to draw a whole bunch of circles and lines. He made a formula, which is kind of like a special recipe, that lets us plug in the angle we want to find the sine of and get a pretty good answer.

The formula looks like this: sin(x) = 16x(π - x) / [5π^2 - 4x(π - x)].

Okay, that's a lot of letters and numbers all mashed together, so let's break it down.

The first thing to notice is the "sin(x)" part of the formula. This just means that we're trying to find the sine of an angle, and we can plug in the value of that angle where the "x" is.

The other part of the formula is a bit more complicated. Bhaskara i used something called "pi," which is a special number that shows up a lot in math. Think of it as a super-delicious pizza that you want to divide into pieces. Pi tells you how many slices you can make, and it's always the same no matter how big or small the pizza is.

The formula has a bunch of pi's and also some numbers that we don't really need to worry about for now. The important thing is that we can use this formula to get a pretty good estimate of the sine of an angle without having to draw lots of circles and lines.

So there you have it, a basic explanation of Bhaskara i's sine approximation formula. Just remember that it's a special recipe that lets us figure out the sine of an angle, and it has pi and some other numbers in it that we don't need to worry about too much.