### 19.3 Trigonometry

Octave provides the following trigonometric functions. Angles are
specified in radians. To convert from degrees to radians multipy by
`pi/180`

(e.g. `sin (30 * pi/180)`

returns the sine of 30 degrees).

— Mapping Function:

**sin** (

`x`)

Compute the sine of each element of `x`.

— Mapping Function:

**cos** (

`x`)

Compute the cosine of each element of `x`.

— Mapping Function:

**tan** (

`z`)

Compute tangent of each element of `x`.

— Mapping Function:

**sec** (

`x`)

Compute the secant of each element of `x`.

— Mapping Function:

**csc** (

`x`)

Compute the cosecant of each element of `x`.

— Mapping Function:

**cot** (

`x`)

Compute the cotangent of each element of `x`.

— Mapping Function:

**asin** (

`x`)

Compute the inverse sine of each element of `x`.

— Mapping Function:

**acos** (

`x`)

Compute the inverse cosine of each element of `x`.

— Mapping Function:

**atan** (

`x`)

Compute the inverse tangent of each element of `x`.

— Mapping Function:

**asec** (

`x`)

Compute the inverse secant of each element of `x`.

— Mapping Function:

**acsc** (

`x`)

Compute the inverse cosecant of each element of `x`.

— Mapping Function:

**acot** (

`x`)

Compute the inverse cotangent of each element of `x`.

— Mapping Function:

**sinh** (

`x`)

Compute the inverse hyperbolic sine of each element of `x`.

— Mapping Function:

**cosh** (

`x`)

Compute the hyperbolic cosine of each element of `x`.

— Mapping Function:

**tanh** (

`x`)

Compute hyperbolic tangent of each element of `x`.

— Mapping Function:

**sech** (

`x`)

Compute the hyperbolic secant of each element of `x`.

— Mapping Function:

**csch** (

`x`)

Compute the hyperbolic cosecant of each element of `x`.

— Mapping Function:

**coth** (

`x`)

Compute the hyperbolic cotangent of each element of `x`.

— Mapping Function:

**asinh** (

`x`)

Compute the inverse hyperbolic sine of each element of `x`.

— Mapping Function:

**acosh** (

`x`)

Compute the inverse hyperbolic cosine of each element of `x`.

— Mapping Function:

**atanh** (

`x`)

Compute the inverse hyperbolic tangent of each element of `x`.

— Mapping Function:

**asech** (

`x`)

Compute the inverse hyperbolic secant of each element of `x`.

— Mapping Function:

**acsch** (

`x`)

Compute the inverse hyperbolic cosecant of each element of `x`.

— Mapping Function:

**acoth** (

`x`)

Compute the inverse hyperbolic cotangent of each element of `x`.

Each of these functions expect a single argument. For matrix arguments,
they work on an element by element basis. For example,

sin ([1, 2; 3, 4])
=> 0.84147 0.90930
0.14112 -0.75680

— Mapping Function:

**atan2** (

`y, x`)

Compute atan (`y` / `x`) for corresponding elements of `y`
and `x`. The result is in range -pi to pi.