Index for Section 3

Alphabetical listing for E

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exp(3)
NAME
  exp, expm1, log, log2, log10, log1p, pow - Exponential, logarithm, and
  power functions

SYNOPSIS
  #include <math.h>

  double exp(
	  double x );

  float expf(
	  float x );

  long double expl(
	  long double x );

  double expm1(
	  double x );

  float expm1f(
	  float x );

  long double expm1l(
	  long double x );

  double log(
	  double x );

  float logf(
	  float x );

  long double logl(
	  long double x );

  double log2(
	  double x );

  float log2f(
	  float x );

  long double log2l(
	  long double x );

  double log10(
	  double x );

  float log10f(
	  float x );

  long double log10l(
	  long double x );

  double log1p(
	  double y );

  float log1pf(
	  float y );

  long double log1pl(
	  long double y );

  double pow(
	  double x,
	  double y );

  float powf(
	  float x,
	  float y );

  long double powl(
	  long double x,
	  long double y );

LIBRARY
  Math Library (libm)

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  exp():  XPG4

  expm1():  XPG4-UNIX

  log():  XPG4

  log10():  XPG4

  log1p():  XPG4-UNIX

  pow():  XPG4

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

DESCRIPTION
  The exp(), expf(), and expl() 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(), expm1f(), and expm1l() functions compute exp(x) - 1
  accurately, even for tiny x.

  The log(), logf(), and logl() functions compute the natural (base e)
  logarithm of x.

  The log2(), log2f(), and log2l() functions compute the base 2 logarithm of
  x.

  The log10(), log10f(), and log10l() functions compute the common (base 10)
  logarithm of x.

  The log1p(), log1pf(), and log1pl() functions compute log(1+y) accurately,
  even for tiny y.

  The pow(), powf(), and powl() functions raise a floating-point base x to a
  floating-point exponent y. The value of pow(x,y) is computed as e**(yln(x))
  for positive x. If x is 0 or negative, see your language reference manual.

  Passing a NaN input value to pow() produces a NaN result for y not equal to
  0. For pow(NaN,0), see your language reference manual.

  The following table describes function behavior in response to exceptional
  arguments:

  ___________________________________________________________________________
  Function			  Exceptional Argument

							      Routine
							      Behavior
  ___________________________________________________________________________
							      Overflow

  exp(), expf(), expl()

				  x > ln(max_float)
				  x < ln(min_float)	      Underflow

  exp(), expf(), expl()
							      Overflow

  expm1(), expm1f(), expm1l ()

				  x > ln(max_float)
				  x < ln(min_float)	      Underflow

  expm1(), expm1f(), expm1l ()
				  x < 0

  log(), logf(), logl()

							      Invalid
							      argument
				  x = 0			      Overflow

  log(), logf(), logl()
				  x < 0

  log2(), log2f(), log2l ()

							      Invalid
							      argument
				  x = 0			      Overflow

  log2(), logf2(), log2l ()
				  x < 0

  log10(), log10f(), log10l ()

							      Invalid
							      argument
				  x = 0			      Overflow

  log10(), log10f(), log10l ()
				  1+y < 0

  log1p(), log1pf(), log1pl ()

							      Invalid
							      argument
				  1+y = 0		      Overflow

  log1p(), log1pf(), log1pl ()
							      Overflow

  pow(), powf(), powl()

				  y ln(x) > ln(max_float)
							      Underflow

  pow(), powf(), powl()

				  y ln(x) < ln(min_float)
  ___________________________________________________________________________

  The following table lists boundary values used by these functions:

  __________________________________________________________________
  Value Name	  Data Type   Hexadecimal Value	  Decimal Value
  __________________________________________________________________
  ln(max_float)	  S_FLOAT     42B17218		  88.7228391
		  T_FLOAT     40862E42FEFA39EF	  709.7827128933840
  ln(min_float)	  S_FLOAT     C2CE8ED0		  -103.2789
		  T_FLOAT     C0874385446D71C3	  -744.4400719213813
  __________________________________________________________________

Index for Section 3

Alphabetical listing for E

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