numpy.arcsinh(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj]) = <ufunc 'arcsinh'>
Inverse hyperbolic sine elementwise.
Parameters: 


Returns: 

arcsinh
is a multivalued function: for each x
there are infinitely many numbers z
such that sinh(z) = x
. The convention is to return the z
whose imaginary part lies in [pi/2, pi/2]
.
For realvalued input data types, arcsinh
always returns real output. For each value that cannot be expressed as a real number or infinity, it returns nan
and sets the invalid
floating point error flag.
For complexvalued input, arccos
is a complex analytical function that has branch cuts [1j, infj]
and [1j, infj]
and is continuous from the right on the former and from the left on the latter.
The inverse hyperbolic sine is also known as asinh
or sinh^1
.
[1]  M. Abramowitz and I.A. Stegun, “Handbook of Mathematical Functions”, 10th printing, 1964, pp. 86. http://www.math.sfu.ca/~cbm/aands/ 
[2]  Wikipedia, “Inverse hyperbolic function”, https://en.wikipedia.org/wiki/Arcsinh 
>>> np.arcsinh(np.array([np.e, 10.0])) array([ 1.72538256, 2.99822295])
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