The cmath.asinh() function to calculate the inverse hyperbolic sine of a given complex number. The input number can be real or complex but the returned value will always be complex.

x The value(real or complex) whose inverse hyperbolic sine we want.

The function returns a  complex value representing the hyperbolic sine of in radians. If is a real number, the returned complex value will have 0j as its imaginary part.

import cmath

print(cmath.asinh(1 + 2j))

It is important to note that the cmath(complex math) module is made for working primarily with complex numbers. If you are working with real numbers, the math.asinh() maybe more relevant.