View source for Relationship between sech and sec

==Theorem==
The following formula holds:
$$\mathrm{sech}(z)=\sec(iz),$$
where $\mathrm{sech}$ denotes the [[sech|hyperbolic secant]] and $\sec$ denotes the [[secant]].

==Proof==

==References==
* {{BookReference|Handbook of mathematical functions|1964|Milton Abramowitz|author2=Irene A. Stegun|prev=Relationship between csch and csc|next=Relationship between coth and cot}}: 4.5.11

* {{BookReference|Handbook of mathematical functions|1964|Milton Abramowitz|author2=Irene A. Stegun|prev=Relationship between sech and sec|next=}}: 4.5.12

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