# Supposedly simple algebra...

• July 19th 2012, 03:03 AM
ebb
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)
• July 19th 2012, 03:16 AM
girdav
Re: Supposedly simple algebra...
$(x^2-1)^k$ 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.
• July 22nd 2012, 02:56 AM
ebb
Re: Supposedly simple algebra...
Thank you - a great help!