ELI5: Explain Like I'm 5

Polynomials calculating sums of powers of arithmetic progressions

Okay kiddo, let me explain this to you. Polynomials are just a fancy way of saying we're gonna play with numbers and letters in a certain way. The letters we use are usually x and y, and the numbers we use can be any number like 1, 2, 3, or even fractions like 1/2, 3/4, and so on.

Now, we also have this thing called an arithmetic progression. Think of it like a bunch of numbers that follow a pattern. For example, if we start with the number 2 and we add 3 to it each time, we get the numbers 2, 5, 8, 11, and so on. That's an arithmetic progression!

So, what we can do is use polynomials to figure out the sum of all the numbers in an arithmetic progression. Let's say we want to find the sum of all the numbers in the progression 2, 5, 8, 11. We can write a polynomial like this: 3x + 2. Why 3x + 2, you ask? Well, that's because we're adding 3 to each number in the progression, and our starting number is 2. So, we're basically saying that the first number in the progression is 2, and then we'll add 3x to get the second number, 3(2) + 2 = 8, and so on.

Now, if we want to find the sum of all the numbers in this progression, we can use another fancy formula called the sum of an arithmetic progression formula. It looks like this:

Sum = (n/2) * (a + l)

Where n is the number of terms in the progression, a is the first term, and l is the last term.

So, in our case, n = 4, a = 2, and l = 11. Plugging these numbers into the formula, we get:

Sum = (4/2) * (2 + 11)
Sum = 6 * 13
Sum = 78

So, there you have it kiddo! We used polynomials and a fancy formula to figure out the sum of all the numbers in an arithmetic progression. Pretty cool, huh?