Missing Mathf Term ?

I’m creating an equation in my game to determine the targeting speed of a ship. I need to use the inverse hyperbolic sine (sinh^-1, or asinh) but the Mathf class doesn’t seem to have it. Do any of you know of a way I can get this, or find a way around? If you want a better idea what it’s going to be used for here is the equation:

    *targetingSpeed = 40000/(scanResolution * asinh(enemySigniture)^2);*

asinhX = ln(X + sqrt(X^2 + 1))

acoshX = ln(X + sqrt(X^2 - 1))

ln is the natural logarithm and sqrt is the square root.