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fea681da | 1 | .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
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2 | .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk |
3 | .\" <mtk.manpages@gmail.com> | |
fea681da | 4 | .\" |
93015253 | 5 | .\" %%%LICENSE_START(VERBATIM) |
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6 | .\" Permission is granted to make and distribute verbatim copies of this |
7 | .\" manual provided the copyright notice and this permission notice are | |
8 | .\" preserved on all copies. | |
9 | .\" | |
10 | .\" Permission is granted to copy and distribute modified versions of this | |
11 | .\" manual under the conditions for verbatim copying, provided that the | |
12 | .\" entire resulting derived work is distributed under the terms of a | |
13 | .\" permission notice identical to this one. | |
c13182ef | 14 | .\" |
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15 | .\" Since the Linux kernel and libraries are constantly changing, this |
16 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
17 | .\" responsibility for errors or omissions, or for damages resulting from | |
18 | .\" the use of the information contained herein. The author(s) may not | |
19 | .\" have taken the same level of care in the production of this manual, | |
20 | .\" which is licensed free of charge, as they might when working | |
21 | .\" professionally. | |
c13182ef | 22 | .\" |
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23 | .\" Formatted or processed versions of this manual, if unaccompanied by |
24 | .\" the source, must acknowledge the copyright and authors of this work. | |
4b72fb64 | 25 | .\" %%%LICENSE_END |
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26 | .\" |
27 | .\" References consulted: | |
28 | .\" Linux libc source code | |
29 | .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) | |
30 | .\" 386BSD man pages | |
31 | .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) | |
32 | .\" Modified 2002-07-27 by Walter Harms | |
33 | .\" (walter.harms@informatik.uni-oldenburg.de) | |
fe0fefbf | 34 | .TH SQRT 3 2015-03-02 "" "Linux Programmer's Manual" |
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35 | .SH NAME |
36 | sqrt, sqrtf, sqrtl \- square root function | |
37 | .SH SYNOPSIS | |
38 | .nf | |
39 | .B #include <math.h> | |
40 | .sp | |
41 | .BI "double sqrt(double " x ); | |
d39541ec | 42 | .br |
fea681da | 43 | .BI "float sqrtf(float " x ); |
d39541ec | 44 | .br |
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45 | .BI "long double sqrtl(long double " x ); |
46 | .fi | |
47 | .sp | |
20c58d70 | 48 | Link with \fI\-lm\fP. |
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49 | .sp |
50 | .in -4n | |
51 | Feature Test Macro Requirements for glibc (see | |
52 | .BR feature_test_macros (7)): | |
53 | .in | |
54 | .sp | |
55 | .ad l | |
56 | .BR sqrtf (), | |
57 | .BR sqrtl (): | |
b90c43a8 | 58 | .RS 4 |
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59 | _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE || |
60 | _POSIX_C_SOURCE\ >=\ 200112L; | |
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61 | .br |
62 | or | |
631c6898 | 63 | .I cc\ -std=c99 |
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64 | .RE |
65 | .ad | |
fea681da | 66 | .SH DESCRIPTION |
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67 | The |
68 | .BR sqrt () | |
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69 | function returns the nonnegative square root of |
70 | .IR x . | |
47297adb | 71 | .SH RETURN VALUE |
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72 | On success, these functions return the square root of |
73 | .IR x . | |
74 | ||
75 | If | |
76 | .I x | |
77 | is a NaN, a NaN is returned. | |
78 | ||
79 | If | |
80 | .I x | |
81 | is +0 (\-0), +0 (\-0) is returned. | |
82 | ||
83 | If | |
84 | .I x | |
85 | is positive infinity, positive infinity is returned. | |
86 | ||
87 | If | |
88 | .I x | |
89 | is less than \-0, | |
efe294cb | 90 | a domain error occurs, |
631c6898 | 91 | and a NaN is returned. |
fea681da | 92 | .SH ERRORS |
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93 | See |
94 | .BR math_error (7) | |
95 | for information on how to determine whether an error has occurred | |
96 | when calling these functions. | |
97 | .PP | |
98 | The following errors can occur: | |
fea681da | 99 | .TP |
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100 | Domain error: \fIx\fP less than \-0 |
101 | .I errno | |
102 | is set to | |
103 | .BR EDOM . | |
104 | An invalid floating-point exception | |
105 | .RB ( FE_INVALID ) | |
106 | is raised. | |
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107 | .SH ATTRIBUTES |
108 | For an explanation of the terms used in this section, see | |
109 | .BR attributes (7). | |
110 | .TS | |
111 | allbox; | |
112 | lbw24 lb lb | |
113 | l l l. | |
114 | Interface Attribute Value | |
115 | T{ | |
116 | .BR sqrt (), | |
117 | .BR sqrtf (), | |
118 | .BR sqrtl () | |
119 | T} Thread safety MT-Safe | |
120 | .TE | |
47297adb | 121 | .SH CONFORMING TO |
9a74e018 | 122 | C99, POSIX.1-2001, POSIX.1-2008. |
e05e3635 | 123 | |
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124 | The variant returning |
125 | .I double | |
126 | also conforms to | |
68e1685c | 127 | SVr4, 4.3BSD, C89. |
47297adb | 128 | .SH SEE ALSO |
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129 | .BR cbrt (3), |
130 | .BR csqrt (3), | |
fea681da | 131 | .BR hypot (3) |