# series expansion of cotx

• October 1st 2009, 02:24 AM
pepsi
series expansion of cotx
hi you,

he expansion for the cosx ... okay got it

but though i can do the long division to get tanx i can't for the series expansion of cotx

maybe you know much more than me

yes?
• October 1st 2009, 07:01 AM
Amer
Quote:

Originally Posted by pepsi
hi you,

he expansion for the cosx ... okay got it

but though i can do the long division to get tanx i can't for this

maybe you know much more than me

$\cot(z)=\sum_{n=0}^{\infty}\frac{(-1)^n 2^{2n} B_{2n}}{(2n)!} z^{2n-1}$