tanh, tanhf, tanhl

 

C

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Thread support (C11)

Technical Specifications

 

Numerics

Common mathematical functions

Floating-point environment

Complex number arithmetics

Random number generation

Type-generic math

 

Common mathematical functions

Functions
Basic operations
abslabsllabsimaxabs (C99) fabs divldivlldivimaxdiv (C99) fmod	remainder (C99) remquo (C99) fma (C99) fmax (C99) fmin (C99) fdim (C99) nannanfnanl (C99)(C99)(C99)
Exponential functions
exp exp2 (C99) expm1 (C99)	log log10 log1p (C99) log2 (C99)
Power functions
sqrt cbrt (C99)	hypot (C99) pow
Trigonometric and hyperbolic functions
sin cos tan asin acos atan atan2	sinh cosh tanh asinh (C99) acosh (C99) atanh (C99)
Error and gamma functions
erf (C99) erfc (C99)	lgamma (C99) tgamma (C99)
Nearest integer floating point operations
ceil floor roundlroundllround (C99)(C99)(C99)	trunc (C99) nearbyint (C99) rintlrintllrint (C99)(C99)(C99)
Floating point manipulation functions
ldexp scalbnscalbln (C99)(C99) ilogb (C99) logb (C99)	frexp modf nextafternexttoward (C99)(C99) copysign (C99)
Classification
fpclassify (C99) isfinite (C99) isinf (C99) isnan (C99) isnormal (C99) signbit (C99)	isgreater (C99) isgreaterequal (C99) isless (C99) islessequal (C99) islessgreater (C99) isunordered (C99)
Types
div_tldiv_tlldiv_timaxdiv_t (C99)(C99)	float_tdouble_t (C99)(C99)
Macro constants
HUGE_VALFHUGE_VALHUGE_VALL (C99)(C99) FP_FAST_FMAFFP_FAST_FMAFP_FAST_FMAL (C99)(C99)(C99) math_errhandlingMATH_ERRNOMATH_ERRNOEXCEPT (C99)(C99)(C99)	INFINITY (C99) NAN (C99) FP_ILOGB0FP_ILOGBNAN (C99)(C99) FP_NORMALFP_SUBNORMALFP_ZEROFP_INFINITEFP_NAN (C99)(C99)(C99)(C99)(C99)

 

Defined in header <math.h>
float       tanhf( float arg );	(1)	(since C99)
double      tanh( double arg );	(2)
long double tanhl( long double arg );	(3)	(since C99)
Defined in header <tgmath.h>
#define tanh( arg )	(4)	(since C99)

1-3) Computes the hyperbolic tangent of arg.

4) Type-generic macro: If the argument has type long double, tanhl is called. Otherwise, if the argument has integer type or the type double, tanh is called. Otherwise, tanhf is called. If the argument is complex, then the macro invokes the corresponding complex function (ctanhf, ctanh, ctanhl).

Parameters

arg

-

floating point value representing a hyperbolic angle

Return value

If no errors occur, the hyperbolic tangent of arg (tanh(arg), or

earg -e-arg

earg +e-arg

) is returned.

If a range error occurs due to underflow, the correct result (after rounding) is returned.

Error handling

Errors are reported as specified in math_errhandling.

If the implementation supports IEEE floating-point arithmetic (IEC 60559),

• if the argument is ±0, ±0 is returned
• If the argument is ±∞, ±1 is returned
• if the argument is NaN, NaN is returned

Notes

POSIX specifies that in case of underflow, arg is returned unmodified, and if that is not supported, an implementation-defined value no greater than DBL_MIN, FLT_MIN, and LDBL_MIN is returned.

Example

Run this code

#include <stdio.h>
#include <math.h>
 
int main(void)
{
    printf("tanh(1) = %f\ntanh(-1) = %f\n", tanh(1), tanh(-1));
    printf("tanh(0.1)*sinh(0.2)-cosh(0.2) = %f\n", tanh(0.1) * sinh(0.2) - cosh(0.2));
    // special values
    printf("tanh(+0) = %f\ntanh(-0) = %f\n", tanh(0.0), tanh(-0.0));
}

Output:

tanh(1) = 0.761594
tanh(-1) = -0.761594
tanh(0.1)*sinh(0.2)-cosh(0.2) = -1.000000
tanh(+0) = 0.000000
tanh(-0) = -0.000000

References

• C11 standard (ISO/IEC 9899:2011):

• 7.12.5.6 The tanh functions (p: 242)

• 7.25 Type-generic math <tgmath.h> (p: 373-375)

• F.10.2.6 The tanh functions (p: 520)

• C99 standard (ISO/IEC 9899:1999):

• 7.12.5.6 The tanh functions (p: 222-223)

• 7.22 Type-generic math <tgmath.h> (p: 335-337)

• F.9.2.6 The tanh functions (p: 457)

• C89/C90 standard (ISO/IEC 9899:1990):

• 4.5.3.3 The tanh function

See also

sinhsinhfsinhl (C99)(C99)	computes hyperbolic sine (sh(x)) (function)
coshcoshfcoshl (C99)(C99)	computes hyperbolic cosine (ch(x)) (function)
atanhatanhfatanhl (C99)(C99)(C99)	computes inverse hyperbolic tangent (artanh(x)) (function)
ctanhctanhfctanhl (C99)(C99)(C99)	computes the complex hyperbolic tangent (function)
C++ documentation for tanh