21.02.2013 Views

Goppa Codes - Department of Mathematics

Goppa Codes - Department of Mathematics

Goppa Codes - Department of Mathematics

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

<strong>Goppa</strong> <strong>Codes</strong> Key One Chung<br />

✬<br />

Now, let’s find points <strong>of</strong> degree 1(rational points) C0(F3).<br />

✫<br />

y 2 − x 3 − 2x − 2 = 0<br />

If x = 0, then y 2 = 2. No such elements in F3.<br />

If x = 1, then y 2 = 2. No such elements in F3.<br />

If x = 2, then y 2 = 2. No such elements in F3.<br />

So, no rational points <strong>of</strong> the type (X : Y : 1).<br />

When Z = 0, −X 3 = 0. So, X = 0.<br />

So, C0(F3) = {P∞ := (0 : 1 : 0)}.<br />

✩<br />

✪<br />

Page 20

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!