- #1
RJLiberator
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Homework Statement
Let g(x) ∈ ℤ[x] have degree at least 2, and let p be a prime number such that:
(i) the leading coefficient of g(x) is not divisible by p.
(ii) every other coefficient of g(x) is divisible by p.
(iii) the constant term of g(x) is not divisible by p^2.
a) Show that if a ∈ ℤ such that [a]_p ≠ [0]_p, then [g(a)]_p ≠ [0]_p.
b) Show that if b ∉ ℤ such that _p = [0]_p, then [g(b)]_p^2 ≠ [0]_p^2.
c) Conclude that g(x) has no roots in ℤ
Homework Equations
The Attempt at a Solution
Well, the problem I am having here is understanding the question at all.
So g(x) exists in Z[x].
What does Z[x] exactly mean?
It has a degree of at least 2, and we have p as a prime number.
We know the leading coefficient of g(x) is NOT divisible by p.
So this means we have C*x^n+...
Where c is not divisible by p.
Every other coefficient of g(x) is divisible by p.
So we have C*x^n + g*x^(n-1)+...
where g IS divisible by p.
The constant term fo g(x) is not divisible by p^2. So we now have
C*x^n + g*x^(n-1)+...+ z
where z is not divisible by p*p.
So we look at question a. If a exists in the integers such that [a]_p cannot equal [0]_p then [g(a)]p cannot equal [0]p.
So we have
C*a^2+g*a+z as an example polynomial.
and here is where I start to break down.
Can't decide what to do from here.