math/acsc
===============================================================================
%% Arc cosecant of argument in radians
1. Usage
-------------------------------------------------------------------------------
```mech:disabled
Y := math/acsc(X)
```
2. Description
-------------------------------------------------------------------------------
Computes the arc cosecant (inverse cosecant) of each element of `X`. The input `X` is interpreted as a numeric value. The result `Y` has the same shape as the input `X`.
3. Input
-------------------------------------------------------------------------------
| Argument | Kind | Description |
|----------|--------------------------|---------------------------------------|
| `X` | `float`, `[float]` | Input value(s). Can be real or complex. For real inputs, values must satisfy `|X| >= 1`. For complex inputs, results are computed accordingly. |
4. Output
-------------------------------------------------------------------------------
| Argument | Kind | Description |
|----------|--------------------------|---------------------------------------|
| `Y` | matches input | Arc cosecant of the input values, expressed in radians. For real inputs, results are in the range `[-π/2, π/2]` excluding `0`. The shape of `Y` matches the shape of `X`. |
5. Examples
-------------------------------------------------------------------------------
(a) Find the arc cosecant of a number
```mech:ex1
y := math/acsc(2.0)
```
(b) Find the arc cosecant for a vector of numbers
```mech:ex2
x := [1, -2, 10]
y := math/acsc(x)
```
(c) Find the arc cosecant for a matrix of numbers
```mech:ex3
x := [2, -3; 4, -5]
y := math/acsc(x)
```
(d) Relationship with asin
```mech:ex4
x := [2, 3, 4]
y := math/acsc(x) # equivalent to asin(1/x)
```
6. Details
-------------------------------------------------------------------------------
The arc cosecant (inverse cosecant) function returns the angle whose cosecant is the specified value.
For real numbers $$x$$ with $$|x| \geq 1$$:
$$ y = acsc(x)
means $$ csc(y) = x $$, with $$ y \in [-\pi/2, \pi/2] $$ and $$ y \neq 0 $$.
It can be expressed in terms of arcsine:
$$ acsc(x) = asin(1/x)
for $$x \neq 0$$.
For complex numbers, arc cosecant can be expressed as:
$$ acsc(z) = -i \ln \left( \frac{i}{z} + \sqrt{1 - \frac{1}{z^2}} \right)
This definition extends the function beyond real numbers, allowing it to handle complex inputs.