### Header Files and Constants for the complex and c_exception Classes

To use the complex or c_exception classes, you must either:

- Specify the complex.h file in a source configuration file directive that applies to any build target using these classes.
- Include the following statement in any file using these classes:

      #include <complex.h>

#### Constants Defined in complex.h

The following table lists the mathematical constants that the Complex Mathematics Library defines.

Constant Name |  | Description
M_E |  | The constant e
M_LOG2E |  | The logarithm of e to the base 2
M_LOG10E |  | The logrithm of e to the base 10
M_LN2 |  | The natural logrithm of 2
M_LN10 |  | The natural logrithm of 10
M_PI |  | pi
M_PI_2 |  | pi divided by two
M_PI_4 |  | pi divided by four
M_1_PI |  | 1/pi
M_2_PI |  | 2/pi
M_2_SQRTPI |  | 2 divided by the square root of pi
M_SQURT2 |  | The square root of 2
M_SQURT1_2 |  | The square root of 1/2