expm1, expm1f, expm1l
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Computes the base-e exponential of a value, minus one.
double expm1( double x ); float expm1( float x ); // C++ only long double expm1( long double x ); // C++ only float expm1f( float x ); long double expm1l( long double x );
Parameters
x
The floating-point exponential value.
The expm1 functions return a floating-point value that represents ex – 1, if successful. On overflow, expm1 returns HUGE_VAL, expm1f returns HUGE_VALF, expm1l returns HUGE_VALL, and errno is set to ERANGE. For more information about return codes, see errno, _doserrno, _sys_errlist, and _sys_nerr.
Because C++ allows overloading, you can call overloads of expm1 that take and return float and long double values. In a C program, expm1 always takes and returns a double.
| Routine | Required header |
|---|---|
expm1, expm1f, expm1l | <math.h> |
For additional compatibility information, see Compatibility.
Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.