- `Y = asec (X)`

Compute the inverse secant in radians for each element of `X`.

This is defined as

> > `%asec(z) = acos(1/z)%`

See also: `sec`, `asecd`.

### References

- https://www.mathworks.com/help/matlab/ref/asec.html
- https://octave.sourceforge.io/octave/function/asec.html
- https://mathworld.wolfram.com/InverseTrigonometricFunctions.html
- https://en.wikipedia.org/wiki/Inverse_trigonometric_functions