1tan(3) Library Functions Manual tan(3)
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6 tan, tanf, tanl - tangent function
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9 Math library (libm, -lm)
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12 #include <math.h>
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14 double tan(double x);
15 float tanf(float x);
16 long double tanl(long double x);
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18 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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20 tanf(), tanl():
21 _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
22 || /* Since glibc 2.19: */ _DEFAULT_SOURCE
23 || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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26 These functions return the tangent of x, where x is given in radians.
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29 On success, these functions return the tangent of x.
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31 If x is a NaN, a NaN is returned.
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33 If x is positive infinity or negative infinity, a domain error occurs,
34 and a NaN is returned.
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36 If the correct result would overflow, a range error occurs, and the
37 functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with
38 the mathematically correct sign.
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41 See math_error(7) for information on how to determine whether an error
42 has occurred when calling these functions.
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44 The following errors can occur:
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46 Domain error: x is an infinity
47 errno is set to EDOM (but see BUGS). An invalid floating-point
48 exception (FE_INVALID) is raised.
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50 Range error: result overflow
51 An overflow floating-point exception (FE_OVERFLOW) is raised.
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54 For an explanation of the terms used in this section, see at‐
55 tributes(7).
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57 ┌────────────────────────────────────────────┬───────────────┬─────────┐
58 │Interface │ Attribute │ Value │
59 ├────────────────────────────────────────────┼───────────────┼─────────┤
60 │tan(), tanf(), tanl() │ Thread safety │ MT-Safe │
61 └────────────────────────────────────────────┴───────────────┴─────────┘
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64 C11, POSIX.1-2008.
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67 C99, POSIX.1-2001.
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69 The variant returning double also conforms to SVr4, 4.3BSD, C89.
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72 Before glibc 2.10, the glibc implementation did not set errno to EDOM
73 when a domain error occurred.
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76 acos(3), asin(3), atan(3), atan2(3), cos(3), ctan(3), sin(3)
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80Linux man-pages 6.04 2023-03-30 tan(3)