How to use inverse hyperbolic functions in Ruby

The asinh() function

The asinh() function returns the inverse hyperbolic sine of a number.

The figure below shows the mathematical representation of the asinh() function:

asinh(x)=ln(x+(x2+1))asinh(x) =ln(x+√(x^{2}+1))

The acosh() function

The acosh() function returns the inverse hyperbolic cosine of a number.

The figure below shows the mathematical representation of the acosh() function:

acosh(x)=ln(x+(x21))acosh(x) =ln(x+√(x^{2}-1))

The atanh() function

The atanh() function returns the inverse hyperbolic tangent of a number.

The figure below shows the mathematical representation of the atanh() function:

atanh(x)=12ln(1+x1x)atanh(x)=\frac {1}{2}ln(\frac {1+x}{1-x})

Syntax

asinh(angle)
acosh(angle)
atanh(angle)

Parameters

These functions require an angle in radians as a parameter.

  • The angle sent to acosh() should be greater than 1 otherwise it returns domain error.
  • The angle sent to atanh() should be between 1 and -1 otherwise it returns domain error.

Return value

  • The asinh() function returns the inverse hyperbolic sine of the angle sent as a parameter.

  • The acosh() function returns the inverse hyperbolic cosine of the angle sent as a parameter.

  • The atanh() function returns the inverse hyperbolic tangent of the angle sent as a parameter.

Example

The code below demonstrates how to use the inverse hyperbolic functions function in Ruby:

#positive number in radians
print "The value of asinh(0.5) : ", Math.asinh(0.5), "\n"
print "The value of acosh(1.5) : ", Math.acosh(1.5), "\n"
print "The value of atanh(0.5) : ", Math.atanh(0.5), "\n"
#negative number in radians
print "The value of asinh(-0.5) : ", Math.asinh(-0.5), "\n"
print "The value of atanh(-0.5) : ", Math.atanh(-0.5), "\n"
#zero
print "The value of asinh(0) : ", Math.asinh(0), "\n"
print "The value of atanh(0) : ", Math.atanh(0), "\n"

Explanation

  • Lines 2–4 : We calculate the inverse hyperbolic function of the positive number in radians.
  • Lines 7–8 : We calculate the inverse hyperbolic function of the negative number in radians.
  • Lines 11–12 : We calculate the inverse hyperbolic function of the zero in radians.

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