Inverse Hyperbolic Secant

Online calculator for calculating the angle to the inverse hyperbolic secant

ASech Calculator

Domain Restriction

The ASech(x) or inverse hyperbolic secant shows inverse function behavior with domain 0 < x ≤ 1.

Value must be positive and between 0 and 1 (inclusive)
Results
Angle:

ASech Function Curve

Curve of the ASech function

The ASech function starts at (1,0) and increases logarithmically toward infinity.
Domain: (0, 1], Range: [0, ∞)

Inverse Function Behavior of ASech

The inverse hyperbolic secant function exhibits characteristic inverse properties:

  • Domain: (0, 1] (positive values up to 1)
  • Range: [0, ∞) (non-negative angles)
  • Starting Point: ASech(1) = 0
  • Inverse: Sech(ASech(x)) = x for 0 < x ≤ 1
  • Monotonicity: Strictly increasing
  • Growth: Logarithmic divergence to ∞

Logarithmic Representation of ASech Function

The inverse hyperbolic secant function is expressed through logarithmic functions:

Basic Formula
\[\text{ASech}(x) = \ln\left(\frac{1 + \sqrt{1 - x^2}}{x}\right)\]

Natural logarithm expression for 0 < x ≤ 1

Inverse Relation
\[\text{sech}(\text{ASech}(x)) = x\]

For 0 < x ≤ 1

Formulas for the ASech Function

Definition
\[\text{ASech}(x) = \ln\left(\frac{1 + \sqrt{1 - x^2}}{x}\right)\]

Natural logarithm expression for 0 < x ≤ 1

Inverse Relation
\[\text{sech}(\text{ASech}(x)) = x \text{ for } 0 < x \leq 1\] \[\text{ASech}(\text{sech}(y)) = y \text{ for } y \geq 0\]

Fundamental inverse function properties

Derivative
\[\frac{d}{dx} \text{ASech}(x) = -\frac{1}{x\sqrt{1 - x^2}}\]

First derivative for 0 < x < 1

Domain Restriction
\[0 < x \leq 1 \text{ (required for real values)}\]

Returns NaN for x ≤ 0 or x > 1

Limit Behavior
\[\lim_{x \to 0^+} \text{ASech}(x) = +\infty\] \[\text{ASech}(1) = 0\]

Divergent behavior as x approaches 0

Special Values

Important Values
ASech(1) = 0 ASech(0.5) ≈ 1.317 ASech(1/e) ≈ 1.657
Invalid Range
\[x \leq 0 \text{ or } x > 1: \text{NaN}\]

Function undefined outside (0, 1]

Starting Point
\[\text{ASech}(1) = 0\]

Function starts at the point (1, 0)

Properties
  • Inverse function
  • Strictly increasing
  • Logarithmic divergence
  • Domain bounded to (0, 1]
Bell Function Inverse
\[\text{ASech}(x) = \text{ACosh}\left(\frac{1}{x}\right)\]

Relationship to inverse hyperbolic cosine

Applications

Signal processing, probability theory, bell curve analysis, inverse problems.

Detailed Description of the ASech Function

Definition and Input

The inverse hyperbolic secant function ASech(x) is the inverse function of the hyperbolic secant. It exhibits characteristic logarithmic divergence with a restricted domain.

Critical Property: The ASech function requires 0 < x ≤ 1 for real values!
Input

The argument must be a positive number greater than 0 and less than or equal to 1. Values outside this range return NaN (not a valid number).

Result

The result is given in degrees (full circle = 360°) or radians (full circle = 2π). The unit of measurement used is set using the Degrees or Radians menu.

Using the Calculator

Enter a value between 0 and 1 (inclusive). The ASech function calculates the angle whose hyperbolic secant equals the input value.

Mathematical Properties

Function Properties
  • Domain: (0, 1] (positive values up to 1)
  • Range: [0, ∞) (non-negative)
  • Starting Point: ASech(1) = 0
  • Monotonicity: Strictly increasing
Bell Function Inverse Properties
  • Inverse of bell-shaped Sech function
  • Logarithmic divergence as x → 0⁺
  • Related to ACosh by reciprocal argument
  • Domain restricted to positive unit interval
Applications
  • Signal Processing: Bell curve analysis
  • Probability Theory: Inverse bell distributions
  • Mathematical Physics: Soliton theory
  • Engineering: Shape analysis problems
Practical Notes
  • Domain restriction: 0 < x ≤ 1 (undefined outside)
  • Starting value: ASech(1) = 0
  • Divergence: ASech(x) → ∞ as x → 0⁺
  • Inverse relation: Sech(ASech(x)) = x for 0 < x ≤ 1

Calculation Examples

Valid Values

ASech(1) = 0

ASech(0.5) ≈ 1.317

ASech(0.1) ≈ 2.993

Special Values

ASech(1/e) ≈ 1.657

ASech(0.6) ≈ 1.074

ASech(2/3) ≈ 0.881

Invalid Inputs

ASech(0) = NaN

ASech(-0.5) = NaN

ASech(2) = NaN

Mathematical and Physical Applications

Bell Curve Analysis

Inverse Bell Functions:

Soliton pulse analysis

Shape parameter extraction

Application: Analyzing bell-shaped signals and pulses.

Probability Theory

Distribution Analysis:

Inverse probability functions

Bell-shaped distribution inversions

Example: Parameter estimation in bell distributions.

Important Mathematical Relationships

Inverse Function Properties
\[\text{sech}(\text{ASech}(x)) = x \text{ for } 0 < x \leq 1\] \[\text{ASech}(\text{sech}(y)) = y \text{ for } y \geq 0\]

Identities: Fundamental inverse relationships.

Calculus Properties
\[\frac{d}{dx}\text{ASech}(x) = -\frac{1}{x\sqrt{1-x^2}}\] \[\text{ASech}(x) = \text{ACosh}\left(\frac{1}{x}\right)\]

Derivative: Involves reciprocal and square root.


IT Functions

Decimal, Hex, Bin, Octal conversionShift bits left or rightSet a bitClear a bitBitwise ANDBitwise ORBitwise exclusive OR

Special functions

AiryDerivative AiryBessel-IBessel-IeBessel-JBessel-JeBessel-KBessel-KeBessel-YBessel-YeSpherical-Bessel-J Spherical-Bessel-YHankelBetaIncomplete BetaIncomplete Inverse BetaBinomial CoefficientBinomial Coefficient LogarithmErfErfcErfiErfciFibonacciFibonacci TabelleGammaInverse GammaLog GammaDigammaTrigammaLogitSigmoidDerivative SigmoidSoftsignDerivative SoftsignSoftmaxStruveStruve tableModified StruveModified Struve tableRiemann Zeta

Hyperbolic functions

ACoshACothACschASechASinhATanhCoshCothCschSechSinhTanh

Trigonometrische Funktionen

ACosACotACscASecASinATanCosCotCscSecSinSincTanDegree to RadianRadian to Degree