Difference between revisions of "Relationship between cosh and cos"

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==References==
 
==References==
* {{BookReference|Handbook of mathematical functions|1964|Milton Abramowitz|author2=Irene A. Stegun|prev=Relationship between sinh and sin|next=Relationship between tanh and tan}}: 4.5.8
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* {{BookReference|Handbook of mathematical functions|1964|Milton Abramowitz|author2=Irene A. Stegun|prev=Relationship between sinh and sin|next=Relationship between tanh and tan}}: $4.5.8$
  
 
[[Category:Theorem]]
 
[[Category:Theorem]]
 
[[Category:Unproven]]
 
[[Category:Unproven]]

Latest revision as of 19:38, 22 November 2016

Theorem

The following formula holds: $$\cosh(z)=\cos(iz),$$ where $\cosh$ is the hyperbolic cosine and $\cos$ is the cosine.

Proof

References