The Single UNIX ® Specification, Version 2
Copyright © 1997 The Open Group


exp - exponential function


#include <math.h>

double exp(double x);


The exp() function computes the exponent of x, defined as ex.

An application wishing to check for error situations should set errno to 0 before calling exp(). If errno is non-zero on return, or the return value is NaN, an error has occurred.


Upon successful completion, exp() returns the exponential value of x.

If the correct value would cause overflow, exp() returns HUGE_VAL and sets errno to [ERANGE].

If the correct value would cause underflow, exp() returns 0 and may set errno to [ERANGE].

If x is NaN, NaN is returned and errno may be set to [EDOM].


The exp() function will fail if:
The result overflows.

The exp() function may fail if:

The value of x is NaN.
The result underflows.

No other errors will occur.








isnan(), log(), <math.h>.


Derived from Issue 1 of the SVID.

UNIX ® is a registered Trademark of The Open Group.
Copyright © 1997 The Open Group
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