| Calling Sequence
| arctan(y)
arctan(y,x)
|
| Parameters
| | Name | Type | Description |
|
| y
| numeric | a numerical value |
| x
| numeric | an optional numerical value |
|
| Return Type
| numeric |
| Synopsis
| This function, with a single argument,
computes the inverse tangent function
defined by: tan(arctan(y)) = y. The value returned by arctan is
between -Pi/2 <= arctan(y) <= Pi/2.
With two arguments, it computes the inverse tangent function
defined by: tan(arctan(y,x)) = y/x when x <> 0. The value returned
by arctan with two arguments is between -Pi < arctan(y,x) <= Pi.
Arctan with two arguments computes the
principal value of the argument of the complex number x+I*y |
| References
| Handbook of Mathematical Functions, M. Abramowitz and
I. Stegun, Ch 4.4 |
| Examples
| > arctan(0);
0
> arctan(1);
0.7854
> arctan(1,0);
1.5708
> arctan(-1,0);
-1.5708
> arctan(1,1);
0.7854
> arctan(-1,-1);
-2.3562
|
| See also
| arcsin, cos, sin, tan |