'\" t .\" Copyright, The contributors to the Linux man-pages project .\" .\" SPDX-License-Identifier: Linux-man-pages-copyleft .\" .TH sinh 3 2025-05-06 "Linux man-pages 6.14" .SH NAME sinh, sinhf, sinhl \- hyperbolic sine function .SH LIBRARY Math library .RI ( libm ,\~ \-lm ) .SH SYNOPSIS .nf .B #include .P .BI "double sinh(double " x ); .BI "float sinhf(float " x ); .BI "long double sinhl(long double " x ); .fi .P .RS -4 Feature Test Macro Requirements for glibc (see .BR feature_test_macros (7)): .RE .P .BR sinhf (), .BR sinhl (): .nf _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE .fi .SH DESCRIPTION These functions return the hyperbolic sine of .IR x , which is defined mathematically as: .P .nf sinh(x) = (exp(x) \- exp(\-x)) / 2 .fi .SH RETURN VALUE On success, these functions return the hyperbolic sine of .IR x . .P If .I x is a NaN, a NaN is returned. .P If .I x is +0 (\-0), +0 (\-0) is returned. .P If .I x is positive infinity (negative infinity), positive infinity (negative infinity) is returned. .P If the result overflows, a range error occurs, and the functions return .BR HUGE_VAL , .BR HUGE_VALF , or .BR HUGE_VALL , respectively, with the same sign as .IR x . .\" .\" POSIX.1-2001 documents an optional range error (underflow) .\" for subnormal x; .\" glibc 2.8 does not do this. .SH ERRORS See .BR math_error (7) for information on how to determine whether an error has occurred when calling these functions. .P The following errors can occur: .TP Range error: result overflow .I errno is set to .BR ERANGE . An overflow floating-point exception .RB ( FE_OVERFLOW ) is raised. .SH ATTRIBUTES For an explanation of the terms used in this section, see .BR attributes (7). .TS allbox; lbx lb lb l l l. Interface Attribute Value T{ .na .nh .BR sinh (), .BR sinhf (), .BR sinhl () T} Thread safety MT-Safe .TE .SH STANDARDS C11, POSIX.1-2008. .SH HISTORY C99, POSIX.1-2001. .P The variant returning .I double also conforms to SVr4, 4.3BSD, C89. .SH SEE ALSO .BR acosh (3), .BR asinh (3), .BR atanh (3), .BR cosh (3), .BR csinh (3), .BR tanh (3)