Relationship between cosh and cos
From specialfunctionswiki
Theorem: The following formula holds: $$\cosh(z)=\cos(iz),$$ where $\cosh$ is the hyperbolic cosine and $\cos$ is the cosine.
Proof: █
Theorem: The following formula holds: $$\cosh(z)=\cos(iz),$$ where $\cosh$ is the hyperbolic cosine and $\cos$ is the cosine.
Proof: █
