# Extension degree over function field

Hello!

I would like to compute the extension degree over a function field.

So I use the commend "degree()". But I found it didn't work well. It produces always just the degree of the polynomial.

For example,

```
sage: K.<x> = FunctionField(QQ)
sage: R.<y> = K[]
sage: L.<y> = K.extension(y^2 - (x^2)); L
Function field in y defined by y^2 - x^2
sage: L.degree()
2
```

In fact, the extension degree [L:K] = 1.

What's wrong?

I'd appreciate it if you could let me know how to compute the extension degree over a function field?

Thank you!

By y^2 - x^2 = 0, it means y = x or y = -x, the degree is one then.