Consider n-dimensional finite affine space: F(n,p) over the
field with prime p-elements.
a. Show tha if l and l' are two lines in F(n,p) containing the
origin 0, then either l intersection l' ={0} or l=l'
b. how many points lie on each line through the origin in
F(n,p)?
c. derive a formula for L(n,p), the number of lines through the
origin in F(n,p)
5. Let n = 60, not a product of distinct prime numbers.
Let Bn= the set of all positive
divisors of n. Define addition and multiplication to be lcm and gcd
as well. Now show
that Bn cannot consist of a Boolean algebra under those two
operators.
Hint: Find the 0 and 1 elements first. Now find an element of Bn
whose complement
cannot be found to satisfy both equalities, no matter how we define
the complement
operator.
Let gcd(a, p) = 1 with p a prime. Show that if a has at least
one square root, then a has exactly 2 roots. [hint: look at
generators or use x^2 = y^2 (mod p) and use the fact that ab = 0
(mod p) the one of a or b must be 0(why?) ]
a) Prove by induction that if a product of n polynomials is
divisible by an irreducible polynomial p(x) then at least one of
them is divisible by p(x). You can assume without a proof that this
fact is true for two polynomials.
b) Give an example of three polynomials a(x), b(x) and c(x), such
that c(x) divides a(x) ·b(x), but c(x) does not divide neither a(x)
nor b(x).