### 5.25.15 List of factors : factors

factors has either a polynomial or a list of polynomials as argument.
factors returns a list containing the factors of the polynomial and their exponents.
Input :

factors(x`^`2+2*x+1)

Output :

[x+1,2]

Input :

factors(x`^`4-2*x`^`2+1)

Output :

[x+1,2,x-1,2]

Input :

factors([x`^`3-2*x`^`2+1,x`^`2-x])

Output :

[[x-1,1,x`^`2-x-1,1],[x,1,x-1,1]]

Input :

factors([x`^`2,x`^`2-1])

Output :

[[x,2],[x+1,1,x-1,1]]