Given: $(x^2-1)^l$
I need to factor this to return $(x+1)^l(x-1)^l$. I tried binomial expansion on both the given polynomial and the first term of the answer, but I can't make a connection as to what I need to do next. I feel like a binomial expansion is not the right way to go.
Screenshot of the problem from the book, Mathematical Methods in the Physical Sciences, Mary Boas:
