we have the question that 'if F is a field with char 0, provethat prime subfield of F is isomorphic to the field of Q'. Ialready figure out the answer. BUT from the question I have otherquestion have risen in my brain. 1. what are the officialdefinition of the kernel of a map and the characteristics of afield? 2. what is the link between the kernel and the char? 3. arethey equivalent in some context?
