High School

Let [tex]f[/tex] be a field with 76 elements and let [tex]k[/tex] be a subfield of [tex]f[/tex] with 49 elements. What is the dimension of [tex]f[/tex] as a vector space over [tex]k[/tex]?

Answer :

The dimension of f as a vector space over k is 2.

Here is how:

The dimension of f as a vector space over k is given by the degree of the field extension [f:k]. In this case, [tex]\( [f:k] = \frac{{\text{{dim}}(f)}}{{\text{{dim}}(k)}} \)[/tex].

Given that f has 76 elements and k has 49 elements, the dimension of f as a vector space over k is:

[tex]\[ [f:k] = \frac{{\text{{dim}}(f)}}{{\text{{dim}}(k)}} = \frac{{76}}{{49}} \][/tex]

However, since dimensions must be integers, we need to find the closest integer. The closest integer to [tex]\( \frac{{76}}{{49}} \)[/tex] is 2.

In other words, the dimension of f as a vector space over k is 2.