# Irreducible Polynomials

1. Jul 24, 2009

### lttlbbygurl

I've been trying to work out a bunch of problems that have to do with finding irreducible polynomials, and this one really seemed to stump me...

What is the probability that a random monic polynomial over $$F_3$$ of degree exactly 10 factors into a product of polynomials of degree less than or equal to 2? What is the probability that a random monic polynomial of degree at most 10 factors into such a product?

2. Jul 25, 2009

### g_edgar

Let's do monic polynomials. (Multiply them by 2 to get the other polynomials, and similarly for the other factorizations, so the probability answer is the same.)

How many different monic polynomials of degree exactly 10 are there?

How many different monic polynomials of degree exactly 1?
How many different irreducible monic polynomials of degree exactly 2?

How many different ways can you multiply these to get a polynomial of degree exactly 10?