To show the probability that two integers chosen at random are relatively prime is
.
Proof: It is sufficient to show
.
When we have a polynomial with constant term one, we may rewrite it in factored form as follows:
If
are the roots of a polynomial p(z), then we may write
.
Now examine the power series for the function sin(z)/z.

Well we also know we can rewrite sin(z)/z in terms of its roots to be:

If we examine the quadratic term in each we find that:
