Can someone help me understand the explanations made in the last two paragrapghs, starting from the sentence "Since the factors $P(x)$ and $P(x)-P(0)...$"
I think I need to be more spesific to get an answer..
First of all, can you show that the expressions $P(x)$ and $P(x)-P(0)$ in $f^{(2k)}(x)$ are nonzero for $x=0$ and $x=\pi$? And they must have a factor of $(2n)!$ in the numerator?
