Difference between revisions of "Coth of a sum"

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==References==
 
==References==
* {{BookReference|Handbook of mathematical functions|1964|Milton Abramowitz|author2=Irene A. Stegun|prev=Cosh of a sum|next=Halving identity for sinh}}: $4.5.27$
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* {{BookReference|Handbook of mathematical functions|1964|Milton Abramowitz|author2=Irene A. Stegun|prev=Tanh of a sum|next=Halving identity for sinh}}: $4.5.27$
  
 
[[Category:Theorem]]
 
[[Category:Theorem]]
 
[[Category:Unproven]]
 
[[Category:Unproven]]

Revision as of 23:32, 21 October 2017

Theorem

The following formula holds: $$\coth(z_1+z_2)=\dfrac{\coth(z_1)\coth(z_2)+1}{\cosh(z_1)+\coth(z_2)},$$ where $\coth$ denotes hyperbolic cotangent.

Proof

References