## Cos H FunctionMath Trig Complex Class

```Public Function CosH( _
ByVal vX As Variant _
) As Variant```

### "Hyperbolic Cosine" Hyperbolic cosine of a real or complex number. Inverse of the ACosH function.

Examples:
```    CosH(-1) = 1.54308063481524
CosH(-0.5) = 1.12762596520638
CosH(0) = 1
CosH(0.5) = 1.12762596520638
CosH(1) = 1.54308063481524
CosH(10) = 11013.2329201033
CosH("2.3|-4.5") = "-1.06182495367184|4.82602885468343"```
```    Cosine Function
SinH Function
TanH Function
CscH Function
ACosH Function
HCos Function```
vX: Number whose hyperbolic cosine is returned. Function returns Null if vX is Null or cannot be fixed up to a real or complex number (as defined by the ComplexStringToReals function). Complex numbers are represented within strings as "R|I" where R is the real part and I is the imaginary part.
Return: The result is expressed in radians.
Note: Microsoft named this function HCos within their Derived Math Function help topic.

Definition:

`    (Exponent(X) + Exponent(-X)) / 2`