# feilds

1. ### vector calculus - vector feilds

find the gradient vector feild ∇f of f and sketch it f(x,y) = sqrt(x^2 +y^2)
2. ### A simple problem in algebra from feilds

I need a rigourous proof for the following problem if possible:- Let L be a finite extension of F and let K be a subfeild of L such that it contains F. Show that [K:F] | [L:F] . Please help.