C Math atan() Function
Example
Return the arctangent of different numbers:
printf("%f", atan(0.5));
printf("%f", atan(-0.5));
printf("%f", atan(5));
printf("%f", atan(-5.0));
printf("%f", atan(100.0));
printf("%f", atan(-100.0));
Try it Yourself »
Definition and Usage
The atan() function returns the arctangent of a number in radians.
The atan() function is defined in the <math.h> header file.
Tip: The atan() function only returns angles between -PI/2 and PI/2. The atan2() function can return any angle.
Syntax
One of the following:
atan(double number);
Parameter Values
| Parameter | Description |
|---|---|
| number | Required. Specifies a number. |
Technical Details
| Returns: | A double value representing the arctangent of a number. |
|---|