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Defined in header <math.h> | ||
float tanf(float arg); | (1) | (since C99) |
double tan(double arg); | (2) | |
longdouble tanl(longdouble arg); | (3) | (since C99) |
_Decimal32 tand32( _Decimal32 arg); | (4) | (since C23) |
_Decimal64 tand64( _Decimal64 arg); | (5) | (since C23) |
_Decimal128 tand128( _Decimal128 arg); | (6) | (since C23) |
Defined in header <tgmath.h> | ||
#define tan( arg ) | (7) | (since C99) |
tanl) is called. Otherwise, if the argument has integer type or the typedouble,(2) (tan) is called. Otherwise,(1) (tanf) is called. If the argument is complex, then the macro invokes the corresponding complex function (ctanf,ctan,ctanl).The functions(4-6) are declared if and only if the implementation predefines | (since C23) |
Contents |
| arg | - | floating-point value representing angle in radians |
If no errors occur, the tangent ofarg (tan(arg)) is returned.
The result may have little or no significance if the magnitude ofarg is large. | (until C99) |
If a domain error occurs, an implementation-defined value is returned (NaN where supported).
If a range error occurs due to underflow, the correct result (after rounding) is returned.
Errors are reported as specified inmath_errhandling.
If the implementation supports IEEE floating-point arithmetic (IEC 60559):
The case where the argument is infinite is not specified to be a domain error in C, but it is defined as adomain error in POSIX.
The function has mathematical poles atπ(1/2 + n); however no common floating-point representation is able to representπ/2 exactly, thus there is no value of the argument for which a pole error occurs.
#include <errno.h>#include <fenv.h>#include <math.h>#include <stdio.h> #ifndef __GNUC__#pragma STDC FENV_ACCESS ON#endif int main(void){constdouble pi=acos(-1); // typical usageprintf("tan(pi*1/4) = %+f\n", tan(pi*1/4));// 45 degprintf("tan(pi*3/4) = %+f\n", tan(pi*3/4));// 135 degprintf("tan(pi*5/4) = %+f\n", tan(pi*5/4));// -135 degprintf("tan(pi*7/4) = %+f\n", tan(pi*7/4));// -45 deg // special valuesprintf("tan(+0) = %f\n", tan(0.0));printf("tan(-0) = %f\n", tan(-0.0)); // error handlingfeclearexcept(FE_ALL_EXCEPT);printf("tan(INFINITY) = %f\n", tan(INFINITY));if(fetestexcept(FE_INVALID))puts(" FE_INVALID raised");}
Possible output:
tan(pi*1/4) = +1.000000tan(pi*3/4) = -1.000000tan(pi*5/4) = +1.000000tan(pi*7/4) = -1.000000tan(+0) = 0.000000tan(-0) = -0.000000tan(INFINITY) = -nan FE_INVALID raised
(C99)(C99) | computes sine (\({\small\sin{x} }\)sin(x)) (function)[edit] |
(C99)(C99) | computes cosine (\({\small\cos{x} }\)cos(x)) (function)[edit] |
(C99)(C99) | computes arc tangent (\({\small\arctan{x} }\)arctan(x)) (function)[edit] |
(C99)(C99)(C99) | computes the complex tangent (function)[edit] |
C++ documentation fortan | |
