std::sin

float       sin( float arg );

double      sin( double arg );

long double sin( long double arg );

double      sin( Integral arg );

Computes the sine of arg (measured in radians).

Parameters

Return value

If no errors occur, the sine of arg (sin(arg)) in the range [-1 ; +1], is returned.

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),

• if the argument is ±0, it is returned unmodified
• if the argument is ±∞, NaN is returned and FE_INVALID is raised
• if the argument is NaN, NaN is returned

Notes

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

POSIX also specifies that in case of underflow, arg is returned unmodified, and if that is not supported, an implementation-defined value no greater than DBL_MIN, FLT_MIN, and LDBL_MIN is returned.

Example

#include <iostream>
#include <cmath>
#include <cerrno>
#include <cfenv>
 
#pragma STDC FENV_ACCESS ON
const double pi = std::acos(-1);
int main()
{
    // typical usage
    std::cout << "sin(pi/6) = " << std::sin(pi/6) << '\n'
              << "sin(pi/2) = " << std::sin(pi/2) << '\n'
              << "sin(-3*pi/4) = " << std::sin(-3*pi/4) << '\n';
    // special values
    std::cout << "sin(+0) = " << std::sin(0.0) << '\n'
              << "sin(-0) = " << std::sin(-0.0) << '\n';
    // error handling 
    std::feclearexcept(FE_ALL_EXCEPT);
    std::cout << "sin(INFINITY) = " << std::sin(INFINITY) << '\n';
    if(std::fetestexcept(FE_INVALID)) std::cout << "    FE_INVALID raised\n";
}

sin(pi/6) = 0.5
sin(pi/2) = 1
sin(-3*pi/4) = -0.707107
sin(+0) = 0
sin(-0) = -0
sin(INFINITY) = -nan
    FE_INVALID raised

See also