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

**"Inverse Sine" or "Arcsine" **

Angle whose sine is X.

Inverse of the Sine function.

**Examples:** ASin(-0.5) = -0.523598775598299
ASin(0) = 0
ASin(0.5) = 0.523598775598299
ASin(1) = 1.5707963267949
ASin(1.5) = "1.5707963267949|-0.962423650119205"
ASin(2) = "1.5707963267949|-1.31695789692482"
ASin("2.3|-4.5") = "0.464698842374882|-2.31904592228528"

**See also:** Sine Function
ACos Function
ATan Function
ASinH Function
Arcsin Function

**vX:** Function returns the principal value of the angle whose sine (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 Arcsin within their Derived Math Function help topic. Copyright 1996-1999 Entisoft

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