# Math Help - Supposedly simple algebra...

1. ## Supposedly simple algebra...

I am struggling to see how Pk(x)= [1/(2k(k!))][(dk((x2-1)k)/dxk] = [1/(2k)][2k choose k][xk] + (terms of lower order)
$(x^2-1)^k$ is a polynomial of degree $2k$; when you take the $k$-th derivative it's a polynomial of degree $k$. Now, look at the leading term.