**Public Function ASecH( _
ByVal vX As Variant _
) As Variant**

**"Inverse Hyperbolic Secant" **

Angle whose hyperbolic secant is X.

Inverse of the SecH function.

**Examples:** ASecH(-10) = "1.49011580830027E-10|1.47062890415069"
ASecH(-2) = "1.22124532708767E-15|1.0471975511966"
ASecH(-1) = 0
ASecH(-0.5) = 1.31695789692482
IsNull(ASecH(0)) = True
ASecH(0.5) = 1.31695789692482
ASecH(1) = 0
ASecH(2) = "1.22124532708767E-15|1.0471975511966"
ASecH(10) = "1.49011580830027E-10|1.47062890415069"
ASecH("2.3|-4.5") = "3.32630134369553E-02|1.36272428148542"

**See also:** ASec Function
SecH Function
ASinH Function
ACotH Function
ACscH Function
HArcsec Function

**vX:** Function returns the principal value of the angle whose hyperbolic secant (expressed in radians) is vX. 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.

**Note:** Microsoft named this function HArcsec within their Derived Math Function help topic. Copyright 1996-1999 Entisoft

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