numpy.arcsin#

numpy.arcsin(x,/,out=None,*,where=True,casting='same_kind',order='K',dtype=None,subok=True[,signature])=<ufunc'arcsin'>#

Inverse sine, element-wise.

Parameters:
xarray_like

y-coordinate on the unit circle.

outndarray, None, or tuple of ndarray and None, optional

A location into which the result is stored. If provided, it must havea shape that the inputs broadcast to. If not provided or None,a freshly-allocated array is returned. A tuple (possible only as akeyword argument) must have length equal to the number of outputs.

wherearray_like, optional

This condition is broadcast over the input. At locations where thecondition is True, theout array will be set to the ufunc result.Elsewhere, theout array will retain its original value.Note that if an uninitializedout array is created via the defaultout=None, locations within it where the condition is False willremain uninitialized.

**kwargs

For other keyword-only arguments, see theufunc docs.

Returns:
anglendarray

The inverse sine of each element inx, in radians and in theclosed interval[-pi/2,pi/2].This is a scalar ifx is a scalar.

Notes

arcsin is a multivalued function: for eachx there are infinitelymany numbersz such that\(sin(z) = x\). The convention is toreturn the anglez whose real part lies in [-pi/2, pi/2].

For real-valued input data types,arcsin always returns real output.For each value that cannot be expressed as a real number or infinity,it yieldsnan and sets theinvalid floating point error flag.

For complex-valued input,arcsin is a complex analytic function thathas, by convention, the branch cuts [-inf, -1] and [1, inf] and iscontinuous from above on the former and from below on the latter.

The inverse sine is also known asasin or sin^{-1}.

References

Abramowitz, M. and Stegun, I. A.,Handbook of Mathematical Functions,10th printing, New York: Dover, 1964, pp. 79ff.https://personal.math.ubc.ca/~cbm/aands/page_79.htm

Examples

>>>importnumpyasnp>>>np.arcsin(1)# pi/21.5707963267948966>>>np.arcsin(-1)# -pi/2-1.5707963267948966>>>np.arcsin(0)0.0
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