# Is the method used in Abel's impossibility theorem completely algebraic?

I need a little help. I am looking for answers to these questions.

1) Can you give me a direct PDF resource for read Abel's impossibility theorem (not Abel-Ruffini theorem) ? I can not find. In Wolfram Mathworld I found only this information:

" In general, polynomial equations higher than fourth degree are incapable of algebraic solution in terms of a finite number of additions, subtractions, multiplications, divisions, and root extractions. This was also shown by Ruffini in 1813 (Wells 1986, p. 59) ".

2) What is the difference between Abel's theorem and Abel Ruffini's theorem?

3) Is the method used in Abel's theorem completely algebraic? Do I need to have strong high math knowledge to understand the theorem?

P.S. Maybe everybody knows the answer to these questions. Since I have not a math teacher, I had to ask these questions in MSE. I may not have picked the tags correctly.

Thank you.

• For me Abel-Ruffini for me is the same as Abel's impossibility theorem (and so is it for wikipedia). The proof relies on Galois theory and can also be found on the wikipedia page – Severin Schraven Jun 21 '18 at 10:13
• Yes, I'm confused, too. Why do you think they are any different? – tomasz Jun 21 '18 at 10:14
• @tomasz names are different, I thought so. Because I do not know about the content .. – lone student Jun 21 '18 at 10:17
• @Student: it's really not that uncommon for a concept to have two different names. If you look at the statement of the "impossibility theorem" on Wolfram and the "Abel-Ruffini theorem" on Wikipedia, they are the same. – tomasz Jun 21 '18 at 11:26