numpy.arcsin¶

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

Inverse sine, element-wise.

Parameters:

x : array_like y-coordinate on the unit circle. out : ndarray, 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 orNone,a freshly-allocated array is returned. A tuple (possible only as akeyword argument) must have length equal to the number of outputs. where : array_like, optional Values of True indicate to calculate the ufunc at that position, valuesof False indicate to leave the value in the output alone. **kwargs For other keyword-only arguments, see theufunc docs.

Returns:

angle : ndarray The inverse sine of each element inx, in radians and in theclosed interval[-pi/2,pi/2]. Ifx is a scalar, a scalaris returned, otherwise an array.

See also

sin,cos,arccos,tan,arctan,arctan2,emath.arcsin

Notes

arcsin is a multivalued function: for eachx there are infinitelymany numbersz such that. 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.http://www.math.sfu.ca/~cbm/aands/

Examples

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