View source for Z coth(z) = 2z/(e^(2z)-1) + z

==Theorem==
The following formula holds for $|z|<\pi$:
$$z \mathrm{coth}(z) = z+\dfrac{2z}{e^{2z}-1},$$
where $\mathrm{coth} denotes [[coth|hyperbolic cotangent]] and $e^{2z}$ denotes the [[exponential]]. 

==Proof==

==References==
* {{BookReference|Higher Transcendental Functions Volume I|1953|Arthur Erdélyi|author2=Wilhelm Magnus|author3=Fritz Oberhettinger|author4=Francesco G. Tricomi|prev=findme|next=z coth(z) = sum of 2^(2n)B_(2n) z^(2n)/(2n)!}}: $\S 1.20 (1)$

[[Category:Theorem]]
[[Category:Unproven]]