Returns the base e raised to the power of the argument.

    Format

      #include  <math.h>

      double exp  (double x);

      float expf  (float x); (Integrity servers, Alpha)

      long double expl  (long double x); (Integrity servers, Alpha)

      double expm1  (double x); (Integrity servers, Alpha)

      float expm1f  (float x); (Integrity servers, Alpha)

      long double expm1l  (long double x);
                          (Integrity servers, Alpha)

1 - Argument

 x

    A real value.

2 - Description

    The exp functions compute the value of the exponential function,
    defined as e**x, where e is the constant used as a base for
    natural logarithms.

    The expm1 functions compute exp(x) - 1 accurately, even for tiny
    x.

    If an overflow occurs, the exp functions return the largest
    possible floating-point value and set errno to ERANGE. The
    constant HUGE_VAL is defined in the <math.h> header file to be
    the largest possible floating-point value.

3 - Return Values

    x                  The exponential value of the argument.
    HUGE_VAL           Overflow occurred; errno is set to ERANGE.
    0                  Underflow occurred; errno is set to ERANGE.
    NaN                x is NaN; errno is set to EDOM.