Which were the inputs of Abel Niels Henrick in math?

Question

Mention five at least pleas!

Answer 1

He showed that there is no general algebraic solution to a quintic equation. (a polynomial whose highest degree/power is five)

Abel submitted a paper on the double periodicity of elliptic functions.

Abel proved the convergence of the binomial series (1+x)^m where m is not an integer. (page 15)

Abel is the founder of the theory of elliptic funcions. (page 72)

Developed a general method of solving functional equations.(pgs. 20-23)