From 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 7 Apr 2024 13:41:34 -0500 Subject: new repository --- devdocs/c/numeric%2Fmath%2Ftan.html | 106 ++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 devdocs/c/numeric%2Fmath%2Ftan.html (limited to 'devdocs/c/numeric%2Fmath%2Ftan.html') diff --git a/devdocs/c/numeric%2Fmath%2Ftan.html b/devdocs/c/numeric%2Fmath%2Ftan.html new file mode 100644 index 00000000..74007697 --- /dev/null +++ b/devdocs/c/numeric%2Fmath%2Ftan.html @@ -0,0 +1,106 @@ +

tan, tanf, tanl

Defined in header <math.h> 
float       tanf( float arg );
+		 (1) (since C99) 
double      tan( double arg );
+		 (2) 
long double tanl( long double 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)
+1-6) Computes the tangent of arg (measured in radians).
+7) Type-generic macro: If the argument has type long double, (3) (tanl) is called. Otherwise, if the argument has integer type or the type double, (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 __STDC_IEC_60559_DFP__ (i.e. the implementation supports decimal floating-point numbers).

+		 (since C23)

Parameters

+ +
arg - floating-point value representing angle in radians

Return value

If no errors occur, the tangent of arg (tan(arg)) is returned.

+ + +

The result may have little or no significance if the magnitude of arg 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.

+

Error handling

Errors are reported as specified in math_errhandling.

+

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

+

Notes

The case where the argument is infinite is not specified to be a domain error in C, but it is defined as a domain error in POSIX.

+

The function has mathematical poles at π(1/2 + n); however no common floating-point representation is able to represent π/2 exactly, thus there is no value of the argument for which a pole error occurs.

+

Example

#include <errno.h>
+#include <fenv.h>
+#include <math.h>
+#include <stdio.h>
+ 
+#ifndef __GNUC__
+#pragma STDC FENV_ACCESS ON
+#endif
+ 
+int main(void)
+{
+    const double pi = acos(-1);
+ 
+    // typical usage
+    printf("tan(pi*1/4) = %+f\n", tan(pi * 1 / 4)); //   45 deg
+    printf("tan(pi*3/4) = %+f\n", tan(pi * 3 / 4)); //  135 deg
+    printf("tan(pi*5/4) = %+f\n", tan(pi * 5 / 4)); // -135 deg
+    printf("tan(pi*7/4) = %+f\n", tan(pi * 7 / 4)); //  -45 deg
+ 
+    // special values
+    printf("tan(+0) = %f\n", tan(0.0));
+    printf("tan(-0) = %f\n", tan(-0.0));
+ 
+    // error handling
+    feclearexcept(FE_ALL_EXCEPT);
+    printf("tan(INFINITY) = %f\n", tan(INFINITY));
+    if (fetestexcept(FE_INVALID))
+        puts("    FE_INVALID raised");
+}

Possible output:

+
tan(pi*1/4) = +1.000000
+tan(pi*3/4) = -1.000000
+tan(pi*5/4) = +1.000000
+tan(pi*7/4) = -1.000000
+tan(+0) = 0.000000
+tan(-0) = -0.000000
+tan(INFINITY) = -nan
+    FE_INVALID raised

References

See also

+ + + + +
+
(C99)(C99)
 computes sine (\({\small\sin{x} }\)sin(x))
(function)
+
(C99)(C99)
 computes cosine (\({\small\cos{x} }\)cos(x))
(function)
+
(C99)(C99)
 computes arc tangent (\({\small\arctan{x} }\)arctan(x))
(function)
+
(C99)(C99)(C99)
 computes the complex tangent
(function)
C++ documentation for tan
+

+ © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
+ https://en.cppreference.com/w/c/numeric/math/tan +

+
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