Difference between revisions of "Relationship between tanh and tan"
From specialfunctionswiki
| (One intermediate revision by the same user not shown) | |||
| Line 7: | Line 7: | ||
==References== | ==References== | ||
| + | * {{BookReference|Handbook of mathematical functions|1964|Milton Abramowitz|author2=Irene A. Stegun|prev=Relationship between cosh and cos|next=Relationship between csch and csc}}: $4.5.9$ | ||
[[Category:Theorem]] | [[Category:Theorem]] | ||
[[Category:Unproven]] | [[Category:Unproven]] | ||
Latest revision as of 19:38, 22 November 2016
Theorem
The following formula holds: $$\tanh(z)=-i \tan(iz),$$ where $\tanh$ is the hyperbolic tangent and $\tan$ is the tangent.
Proof
References
- 1964: Milton Abramowitz and Irene A. Stegun: Handbook of mathematical functions ... (previous) ... (next): $4.5.9$
